draft version of skill tool feature

2025-12-19 09:33:53 +00:00 · 2025-12-10 17:18:44 +08:00
parent 5fddcd509c
commit bd6e16d41b
22 changed files with 1891 additions and 9 deletions
--- a/packages/core/src/config/config.ts
+++ b/packages/core/src/config/config.ts
@@ -54,6 +54,7 @@ import { canUseRipgrep } from '../utils/ripgrepUtils.js';
 import { RipGrepTool } from '../tools/ripGrep.js';
 import { ShellTool } from '../tools/shell.js';
 import { SmartEditTool } from '../tools/smart-edit.js';
+import { SkillTool } from '../tools/skill.js';
 import { TaskTool } from '../tools/task.js';
 import { TodoWriteTool } from '../tools/todoWrite.js';
 import { ToolRegistry } from '../tools/tool-registry.js';
@@ -65,6 +66,7 @@ import { WriteFileTool } from '../tools/write-file.js';
 import { ideContextStore } from '../ide/ideContext.js';
 import { InputFormat, OutputFormat } from '../output/types.js';
 import { PromptRegistry } from '../prompts/prompt-registry.js';
+import { SkillManager } from '../skills/skill-manager.js';
 import { SubagentManager } from '../subagents/subagent-manager.js';
 import type { SubagentConfig } from '../subagents/types.js';
 import {
@@ -387,6 +389,7 @@ export class Config {
  private toolRegistry!: ToolRegistry;
  private promptRegistry!: PromptRegistry;
  private subagentManager!: SubagentManager;
+  private skillManager!: SkillManager;
  private fileSystemService: FileSystemService;
  private contentGeneratorConfig!: ContentGeneratorConfig;
  private contentGenerator!: ContentGenerator;
@@ -635,6 +638,7 @@ export class Config {
    }
    this.promptRegistry = new PromptRegistry();
    this.subagentManager = new SubagentManager(this);
+    this.skillManager = new SkillManager(this);

    // Load session subagents if they were provided before initialization
    if (this.sessionSubagents.length > 0) {
@@ -1285,6 +1289,10 @@ export class Config {
    return this.subagentManager;
  }

+  getSkillManager(): SkillManager {
+    return this.skillManager;
+  }
+
  async createToolRegistry(
    sendSdkMcpMessage?: SendSdkMcpMessage,
  ): Promise<ToolRegistry> {
@@ -1327,6 +1335,7 @@ export class Config {
    };

    registerCoreTool(TaskTool, this);
+    registerCoreTool(SkillTool, this);
    registerCoreTool(LSTool, this);
    registerCoreTool(ReadFileTool, this);

--- a/packages/core/src/config/storage.ts
+++ b/packages/core/src/config/storage.ts
@@ -121,6 +121,10 @@ export class Storage {
    return path.join(this.getExtensionsDir(), 'qwen-extension.json');
  }

+  getUserSkillsDir(): string {
+    return path.join(Storage.getGlobalQwenDir(), 'skills');
+  }
+
  getHistoryFilePath(): string {
    return path.join(this.getProjectTempDir(), 'shell_history');
  }
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -85,6 +85,9 @@ export * from './tools/tool-registry.js';
 // Export subagents (Phase 1)
 export * from './subagents/index.js';

+// Export skills
+export * from './skills/index.js';
+
 // Export prompt logic
 export * from './prompts/mcp-prompts.js';

@@ -106,6 +109,7 @@ export * from './tools/mcp-client-manager.js';
 export * from './tools/mcp-tool.js';
 export * from './tools/sdk-control-client-transport.js';
 export * from './tools/task.js';
+export * from './tools/skill.js';
 export * from './tools/todoWrite.js';
 export * from './tools/exitPlanMode.js';

--- a/packages/core/src/skills/index.ts
+++ b/packages/core/src/skills/index.ts
@@ -0,0 +1,31 @@
+/**
+ * @license
+ * Copyright 2025 Qwen
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @fileoverview Skills feature implementation
+ *
+ * This module provides the foundation for the skills feature, which allows
+ * users to define reusable skill configurations that can be loaded by the
+ * model via a dedicated Skills tool.
+ *
+ * Skills are stored as directories in `.qwen/skills/` (project-level) or
+ * `~/.qwen/skills/` (user-level), with each directory containing a SKILL.md
+ * file with YAML frontmatter for metadata.
+ */
+
+// Core types and interfaces
+export type {
+  SkillConfig,
+  SkillLevel,
+  SkillValidationResult,
+  ListSkillsOptions,
+  SkillErrorCode,
+} from './types.js';
+
+export { SkillError } from './types.js';
+
+// Main management class
+export { SkillManager } from './skill-manager.js';
--- a/packages/core/src/skills/skill-manager.test.ts
+++ b/packages/core/src/skills/skill-manager.test.ts
@@ -0,0 +1,463 @@
+/**
+ * @license
+ * Copyright 2025 Qwen
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { vi, describe, it, expect, beforeEach, afterEach } from 'vitest';
+import * as fs from 'fs/promises';
+import * as path from 'path';
+import * as os from 'os';
+import { SkillManager } from './skill-manager.js';
+import { type SkillConfig, SkillError } from './types.js';
+import type { Config } from '../config/config.js';
+import { makeFakeConfig } from '../test-utils/config.js';
+
+// Mock file system operations
+vi.mock('fs/promises');
+vi.mock('os');
+
+// Mock yaml parser - use vi.hoisted for proper hoisting
+const mockParseYaml = vi.hoisted(() => vi.fn());
+
+vi.mock('../utils/yaml-parser.js', () => ({
+  parse: mockParseYaml,
+  stringify: vi.fn(),
+}));
+
+describe('SkillManager', () => {
+  let manager: SkillManager;
+  let mockConfig: Config;
+
+  beforeEach(() => {
+    // Create mock Config object using test utility
+    mockConfig = makeFakeConfig({});
+
+    // Mock the project root method
+    vi.spyOn(mockConfig, 'getProjectRoot').mockReturnValue('/test/project');
+
+    // Mock os.homedir
+    vi.mocked(os.homedir).mockReturnValue('/home/user');
+
+    // Reset and setup mocks
+    vi.clearAllMocks();
+
+    // Setup yaml parser mocks with sophisticated behavior
+    mockParseYaml.mockImplementation((yamlString: string) => {
+      // Handle different test cases based on YAML content
+      if (yamlString.includes('allowedTools:')) {
+        return {
+          name: 'test-skill',
+          description: 'A test skill',
+          allowedTools: ['read_file', 'write_file'],
+        };
+      }
+      if (yamlString.includes('name: skill1')) {
+        return { name: 'skill1', description: 'First skill' };
+      }
+      if (yamlString.includes('name: skill2')) {
+        return { name: 'skill2', description: 'Second skill' };
+      }
+      if (yamlString.includes('name: skill3')) {
+        return { name: 'skill3', description: 'Third skill' };
+      }
+      if (!yamlString.includes('name:')) {
+        return { description: 'A test skill' }; // Missing name case
+      }
+      if (!yamlString.includes('description:')) {
+        return { name: 'test-skill' }; // Missing description case
+      }
+      // Default case
+      return {
+        name: 'test-skill',
+        description: 'A test skill',
+      };
+    });
+
+    manager = new SkillManager(mockConfig);
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  const validSkillConfig: SkillConfig = {
+    name: 'test-skill',
+    description: 'A test skill',
+    level: 'project',
+    filePath: '/test/project/.qwen/skills/test-skill/SKILL.md',
+    body: 'You are a helpful assistant with this skill.',
+  };
+
+  const validMarkdown = `---
+name: test-skill
+description: A test skill
+---
+
+You are a helpful assistant with this skill.
+`;
+
+  describe('parseSkillContent', () => {
+    it('should parse valid markdown content', () => {
+      const config = manager.parseSkillContent(
+        validMarkdown,
+        validSkillConfig.filePath,
+        'project',
+      );
+
+      expect(config.name).toBe('test-skill');
+      expect(config.description).toBe('A test skill');
+      expect(config.body).toBe('You are a helpful assistant with this skill.');
+      expect(config.level).toBe('project');
+      expect(config.filePath).toBe(validSkillConfig.filePath);
+    });
+
+    it('should parse content with allowedTools', () => {
+      const markdownWithTools = `---
+name: test-skill
+description: A test skill
+allowedTools:
+  - read_file
+  - write_file
+---
+
+You are a helpful assistant with this skill.
+`;
+
+      const config = manager.parseSkillContent(
+        markdownWithTools,
+        validSkillConfig.filePath,
+        'project',
+      );
+
+      expect(config.allowedTools).toEqual(['read_file', 'write_file']);
+    });
+
+    it('should determine level from file path', () => {
+      const projectPath = '/test/project/.qwen/skills/test-skill/SKILL.md';
+      const userPath = '/home/user/.qwen/skills/test-skill/SKILL.md';
+
+      const projectConfig = manager.parseSkillContent(
+        validMarkdown,
+        projectPath,
+        'project',
+      );
+      const userConfig = manager.parseSkillContent(
+        validMarkdown,
+        userPath,
+        'user',
+      );
+
+      expect(projectConfig.level).toBe('project');
+      expect(userConfig.level).toBe('user');
+    });
+
+    it('should throw error for invalid frontmatter format', () => {
+      const invalidMarkdown = `No frontmatter here
+Just content`;
+
+      expect(() =>
+        manager.parseSkillContent(
+          invalidMarkdown,
+          validSkillConfig.filePath,
+          'project',
+        ),
+      ).toThrow(SkillError);
+    });
+
+    it('should throw error for missing name', () => {
+      const markdownWithoutName = `---
+description: A test skill
+---
+
+You are a helpful assistant.
+`;
+
+      expect(() =>
+        manager.parseSkillContent(
+          markdownWithoutName,
+          validSkillConfig.filePath,
+          'project',
+        ),
+      ).toThrow(SkillError);
+    });
+
+    it('should throw error for missing description', () => {
+      const markdownWithoutDescription = `---
+name: test-skill
+---
+
+You are a helpful assistant.
+`;
+
+      expect(() =>
+        manager.parseSkillContent(
+          markdownWithoutDescription,
+          validSkillConfig.filePath,
+          'project',
+        ),
+      ).toThrow(SkillError);
+    });
+  });
+
+  describe('validateConfig', () => {
+    it('should validate valid configuration', () => {
+      const result = manager.validateConfig(validSkillConfig);
+
+      expect(result.isValid).toBe(true);
+      expect(result.errors).toHaveLength(0);
+    });
+
+    it('should report error for missing name', () => {
+      const invalidConfig = { ...validSkillConfig, name: '' };
+      const result = manager.validateConfig(invalidConfig);
+
+      expect(result.isValid).toBe(false);
+      expect(result.errors).toContain('"name" cannot be empty');
+    });
+
+    it('should report error for missing description', () => {
+      const invalidConfig = { ...validSkillConfig, description: '' };
+      const result = manager.validateConfig(invalidConfig);
+
+      expect(result.isValid).toBe(false);
+      expect(result.errors).toContain('"description" cannot be empty');
+    });
+
+    it('should report error for invalid allowedTools type', () => {
+      const invalidConfig = {
+        ...validSkillConfig,
+        allowedTools: 'not-an-array' as unknown as string[],
+      };
+      const result = manager.validateConfig(invalidConfig);
+
+      expect(result.isValid).toBe(false);
+      expect(result.errors).toContain('"allowedTools" must be an array');
+    });
+
+    it('should warn for empty body', () => {
+      const configWithEmptyBody = { ...validSkillConfig, body: '' };
+      const result = manager.validateConfig(configWithEmptyBody);
+
+      expect(result.isValid).toBe(true); // Still valid
+      expect(result.warnings).toContain('Skill body is empty');
+    });
+  });
+
+  describe('loadSkill', () => {
+    it('should load skill from project level first', async () => {
+      vi.mocked(fs.readdir).mockResolvedValue([
+        { name: 'test-skill', isDirectory: () => true, isFile: () => false },
+      ] as unknown as Awaited<ReturnType<typeof fs.readdir>>);
+      vi.mocked(fs.access).mockResolvedValue(undefined);
+      vi.mocked(fs.readFile).mockResolvedValue(validMarkdown);
+
+      const config = await manager.loadSkill('test-skill');
+
+      expect(config).toBeDefined();
+      expect(config!.name).toBe('test-skill');
+    });
+
+    it('should fall back to user level if project level fails', async () => {
+      vi.mocked(fs.readdir)
+        .mockRejectedValueOnce(new Error('Project dir not found')) // project level fails
+        .mockResolvedValueOnce([
+          { name: 'test-skill', isDirectory: () => true, isFile: () => false },
+        ] as unknown as Awaited<ReturnType<typeof fs.readdir>>); // user level succeeds
+      vi.mocked(fs.access).mockResolvedValue(undefined);
+      vi.mocked(fs.readFile).mockResolvedValue(validMarkdown);
+
+      const config = await manager.loadSkill('test-skill');
+
+      expect(config).toBeDefined();
+      expect(config!.name).toBe('test-skill');
+    });
+
+    it('should return null if not found at either level', async () => {
+      vi.mocked(fs.readdir).mockRejectedValue(new Error('Directory not found'));
+
+      const config = await manager.loadSkill('nonexistent');
+
+      expect(config).toBeNull();
+    });
+  });
+
+  describe('loadSkillForRuntime', () => {
+    it('should load skill for runtime', async () => {
+      vi.mocked(fs.readdir).mockResolvedValueOnce([
+        { name: 'test-skill', isDirectory: () => true, isFile: () => false },
+      ] as unknown as Awaited<ReturnType<typeof fs.readdir>>);
+
+      vi.mocked(fs.access).mockResolvedValue(undefined);
+      vi.mocked(fs.readFile).mockResolvedValue(validMarkdown); // SKILL.md
+
+      const config = await manager.loadSkillForRuntime('test-skill');
+
+      expect(config).toBeDefined();
+      expect(config!.name).toBe('test-skill');
+    });
+
+    it('should return null if skill not found', async () => {
+      vi.mocked(fs.readdir).mockRejectedValue(new Error('Directory not found'));
+
+      const config = await manager.loadSkillForRuntime('nonexistent');
+
+      expect(config).toBeNull();
+    });
+  });
+
+  describe('listSkills', () => {
+    beforeEach(() => {
+      // Mock directory listing for skills directories (with Dirent objects)
+      vi.mocked(fs.readdir)
+        .mockResolvedValueOnce([
+          { name: 'skill1', isDirectory: () => true, isFile: () => false },
+          { name: 'skill2', isDirectory: () => true, isFile: () => false },
+          {
+            name: 'not-a-dir.txt',
+            isDirectory: () => false,
+            isFile: () => true,
+          },
+        ] as unknown as Awaited<ReturnType<typeof fs.readdir>>)
+        .mockResolvedValueOnce([
+          { name: 'skill3', isDirectory: () => true, isFile: () => false },
+          { name: 'skill1', isDirectory: () => true, isFile: () => false },
+        ] as unknown as Awaited<ReturnType<typeof fs.readdir>>);
+
+      vi.mocked(fs.access).mockResolvedValue(undefined);
+
+      // Mock file reading for valid skills
+      vi.mocked(fs.readFile).mockImplementation((filePath) => {
+        const pathStr = String(filePath);
+        if (pathStr.includes('skill1')) {
+          return Promise.resolve(`---
+name: skill1
+description: First skill
+---
+Skill 1 content`);
+        } else if (pathStr.includes('skill2')) {
+          return Promise.resolve(`---
+name: skill2
+description: Second skill
+---
+Skill 2 content`);
+        } else if (pathStr.includes('skill3')) {
+          return Promise.resolve(`---
+name: skill3
+description: Third skill
+---
+Skill 3 content`);
+        }
+        return Promise.reject(new Error('File not found'));
+      });
+    });
+
+    it('should list skills from both levels', async () => {
+      const skills = await manager.listSkills();
+
+      expect(skills).toHaveLength(3); // skill1 (project takes precedence), skill2, skill3
+      expect(skills.map((s) => s.name).sort()).toEqual([
+        'skill1',
+        'skill2',
+        'skill3',
+      ]);
+    });
+
+    it('should prioritize project level over user level', async () => {
+      const skills = await manager.listSkills();
+      const skill1 = skills.find((s) => s.name === 'skill1');
+
+      expect(skill1!.level).toBe('project');
+    });
+
+    it('should filter by level', async () => {
+      const projectSkills = await manager.listSkills({
+        level: 'project',
+      });
+
+      expect(projectSkills).toHaveLength(2); // skill1, skill2
+      expect(projectSkills.every((s) => s.level === 'project')).toBe(true);
+    });
+
+    it('should handle empty directories', async () => {
+      vi.mocked(fs.readdir).mockReset();
+      vi.mocked(fs.readdir).mockResolvedValue(
+        [] as unknown as Awaited<ReturnType<typeof fs.readdir>>,
+      );
+
+      const skills = await manager.listSkills({ force: true });
+
+      expect(skills).toHaveLength(0);
+    });
+
+    it('should handle directory read errors', async () => {
+      vi.mocked(fs.readdir).mockReset();
+      vi.mocked(fs.readdir).mockRejectedValue(new Error('Directory not found'));
+
+      const skills = await manager.listSkills({ force: true });
+
+      expect(skills).toHaveLength(0);
+    });
+  });
+
+  describe('getSkillsBaseDir', () => {
+    it('should return project-level base dir', () => {
+      const baseDir = manager.getSkillsBaseDir('project');
+
+      expect(baseDir).toBe(path.join('/test/project', '.qwen', 'skills'));
+    });
+
+    it('should return user-level base dir', () => {
+      const baseDir = manager.getSkillsBaseDir('user');
+
+      expect(baseDir).toBe(path.join('/home/user', '.qwen', 'skills'));
+    });
+  });
+
+  describe('change listeners', () => {
+    it('should notify listeners when cache is refreshed', async () => {
+      const listener = vi.fn();
+      manager.addChangeListener(listener);
+
+      vi.mocked(fs.readdir).mockResolvedValue(
+        [] as unknown as Awaited<ReturnType<typeof fs.readdir>>,
+      );
+
+      await manager.refreshCache();
+
+      expect(listener).toHaveBeenCalled();
+    });
+
+    it('should remove listener when cleanup function is called', async () => {
+      const listener = vi.fn();
+      const removeListener = manager.addChangeListener(listener);
+
+      removeListener();
+
+      vi.mocked(fs.readdir).mockResolvedValue(
+        [] as unknown as Awaited<ReturnType<typeof fs.readdir>>,
+      );
+
+      await manager.refreshCache();
+
+      expect(listener).not.toHaveBeenCalled();
+    });
+  });
+
+  describe('parse errors', () => {
+    it('should track parse errors', async () => {
+      vi.mocked(fs.readdir).mockResolvedValue([
+        { name: 'bad-skill', isDirectory: () => true, isFile: () => false },
+      ] as unknown as Awaited<ReturnType<typeof fs.readdir>>);
+      vi.mocked(fs.access).mockResolvedValue(undefined);
+      vi.mocked(fs.readFile).mockResolvedValue(
+        'invalid content without frontmatter',
+      );
+
+      await manager.listSkills({ force: true });
+
+      const errors = manager.getParseErrors();
+      expect(errors.size).toBeGreaterThan(0);
+    });
+  });
+});
--- a/packages/core/src/skills/skill-manager.ts
+++ b/packages/core/src/skills/skill-manager.ts
@@ -0,0 +1,452 @@
+/**
+ * @license
+ * Copyright 2025 Qwen
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as fs from 'fs/promises';
+import * as path from 'path';
+import * as os from 'os';
+import { parse as parseYaml } from '../utils/yaml-parser.js';
+import type {
+  SkillConfig,
+  SkillLevel,
+  ListSkillsOptions,
+  SkillValidationResult,
+} from './types.js';
+import { SkillError, SkillErrorCode } from './types.js';
+import type { Config } from '../config/config.js';
+
+const QWEN_CONFIG_DIR = '.qwen';
+const SKILLS_CONFIG_DIR = 'skills';
+const SKILL_MANIFEST_FILE = 'SKILL.md';
+
+/**
+ * Manages skill configurations stored as directories containing SKILL.md files.
+ * Provides discovery, parsing, validation, and caching for skills.
+ */
+export class SkillManager {
+  private skillsCache: Map<SkillLevel, SkillConfig[]> | null = null;
+  private readonly changeListeners: Set<() => void> = new Set();
+  private parseErrors: Map<string, SkillError> = new Map();
+
+  constructor(private readonly config: Config) {}
+
+  /**
+   * Adds a listener that will be called when skills change.
+   * @returns A function to remove the listener.
+   */
+  addChangeListener(listener: () => void): () => void {
+    this.changeListeners.add(listener);
+    return () => {
+      this.changeListeners.delete(listener);
+    };
+  }
+
+  /**
+   * Notifies all registered change listeners.
+   */
+  private notifyChangeListeners(): void {
+    for (const listener of this.changeListeners) {
+      try {
+        listener();
+      } catch (error) {
+        console.warn('Skill change listener threw an error:', error);
+      }
+    }
+  }
+
+  /**
+   * Gets any parse errors that occurred during skill loading.
+   * @returns Map of skill paths to their parse errors.
+   */
+  getParseErrors(): Map<string, SkillError> {
+    return new Map(this.parseErrors);
+  }
+
+  /**
+   * Lists all available skills.
+   *
+   * @param options - Filtering options
+   * @returns Array of skill configurations
+   */
+  async listSkills(options: ListSkillsOptions = {}): Promise<SkillConfig[]> {
+    const skills: SkillConfig[] = [];
+    const seenNames = new Set<string>();
+
+    const levelsToCheck: SkillLevel[] = options.level
+      ? [options.level]
+      : ['project', 'user'];
+
+    // Check if we should use cache or force refresh
+    const shouldUseCache = !options.force && this.skillsCache !== null;
+
+    // Initialize cache if it doesn't exist or we're forcing a refresh
+    if (!shouldUseCache) {
+      await this.refreshCache();
+    }
+
+    // Collect skills from each level (project takes precedence over user)
+    for (const level of levelsToCheck) {
+      const levelSkills = this.skillsCache?.get(level) || [];
+
+      for (const skill of levelSkills) {
+        // Skip if we've already seen this name (precedence: project > user)
+        if (seenNames.has(skill.name)) {
+          continue;
+        }
+
+        skills.push(skill);
+        seenNames.add(skill.name);
+      }
+    }
+
+    // Sort by name for consistent ordering
+    skills.sort((a, b) => a.name.localeCompare(b.name));
+
+    return skills;
+  }
+
+  /**
+   * Loads a skill configuration by name.
+   * If level is specified, only searches that level.
+   * If level is omitted, searches project-level first, then user-level.
+   *
+   * @param name - Name of the skill to load
+   * @param level - Optional level to limit search to
+   * @returns SkillConfig or null if not found
+   */
+  async loadSkill(
+    name: string,
+    level?: SkillLevel,
+  ): Promise<SkillConfig | null> {
+    if (level) {
+      return this.findSkillByNameAtLevel(name, level);
+    }
+
+    // Try project level first
+    const projectSkill = await this.findSkillByNameAtLevel(name, 'project');
+    if (projectSkill) {
+      return projectSkill;
+    }
+
+    // Try user level
+    return this.findSkillByNameAtLevel(name, 'user');
+  }
+
+  /**
+   * Loads a skill with its full content, ready for runtime use.
+   * This includes loading additional files from the skill directory.
+   *
+   * @param name - Name of the skill to load
+   * @param level - Optional level to limit search to
+   * @returns SkillConfig or null if not found
+   */
+  async loadSkillForRuntime(
+    name: string,
+    level?: SkillLevel,
+  ): Promise<SkillConfig | null> {
+    const skill = await this.loadSkill(name, level);
+    if (!skill) {
+      return null;
+    }
+
+    return skill;
+  }
+
+  /**
+   * Validates a skill configuration.
+   *
+   * @param config - Configuration to validate
+   * @returns Validation result
+   */
+  validateConfig(config: Partial<SkillConfig>): SkillValidationResult {
+    const errors: string[] = [];
+    const warnings: string[] = [];
+
+    // Check required fields
+    if (typeof config.name !== 'string') {
+      errors.push('Missing or invalid "name" field');
+    } else if (config.name.trim() === '') {
+      errors.push('"name" cannot be empty');
+    }
+
+    if (typeof config.description !== 'string') {
+      errors.push('Missing or invalid "description" field');
+    } else if (config.description.trim() === '') {
+      errors.push('"description" cannot be empty');
+    }
+
+    // Validate allowedTools if present
+    if (config.allowedTools !== undefined) {
+      if (!Array.isArray(config.allowedTools)) {
+        errors.push('"allowedTools" must be an array');
+      } else {
+        for (const tool of config.allowedTools) {
+          if (typeof tool !== 'string') {
+            errors.push('"allowedTools" must contain only strings');
+            break;
+          }
+        }
+      }
+    }
+
+    // Warn if body is empty
+    if (!config.body || config.body.trim() === '') {
+      warnings.push('Skill body is empty');
+    }
+
+    return {
+      isValid: errors.length === 0,
+      errors,
+      warnings,
+    };
+  }
+
+  /**
+   * Refreshes the skills cache by loading all skills from disk.
+   */
+  async refreshCache(): Promise<void> {
+    const skillsCache = new Map<SkillLevel, SkillConfig[]>();
+    this.parseErrors.clear();
+
+    const levels: SkillLevel[] = ['project', 'user'];
+
+    for (const level of levels) {
+      const levelSkills = await this.listSkillsAtLevel(level);
+      skillsCache.set(level, levelSkills);
+    }
+
+    this.skillsCache = skillsCache;
+    this.notifyChangeListeners();
+  }
+
+  /**
+   * Parses a SKILL.md file and returns the configuration.
+   *
+   * @param filePath - Path to the SKILL.md file
+   * @param level - Storage level
+   * @returns SkillConfig
+   * @throws SkillError if parsing fails
+   */
+  parseSkillFile(filePath: string, level: SkillLevel): Promise<SkillConfig> {
+    return this.parseSkillFileInternal(filePath, level);
+  }
+
+  /**
+   * Internal implementation of skill file parsing.
+   */
+  private async parseSkillFileInternal(
+    filePath: string,
+    level: SkillLevel,
+  ): Promise<SkillConfig> {
+    let content: string;
+
+    try {
+      content = await fs.readFile(filePath, 'utf8');
+    } catch (error) {
+      const skillError = new SkillError(
+        `Failed to read skill file: ${error instanceof Error ? error.message : 'Unknown error'}`,
+        SkillErrorCode.FILE_ERROR,
+      );
+      this.parseErrors.set(filePath, skillError);
+      throw skillError;
+    }
+
+    return this.parseSkillContent(content, filePath, level);
+  }
+
+  /**
+   * Parses skill content from a string.
+   *
+   * @param content - File content
+   * @param filePath - File path for error reporting
+   * @param level - Storage level
+   * @returns SkillConfig
+   * @throws SkillError if parsing fails
+   */
+  parseSkillContent(
+    content: string,
+    filePath: string,
+    level: SkillLevel,
+  ): SkillConfig {
+    try {
+      // Split frontmatter and content
+      const frontmatterRegex = /^---\n([\s\S]*?)\n---\n([\s\S]*)$/;
+      const match = content.match(frontmatterRegex);
+
+      if (!match) {
+        throw new Error('Invalid format: missing YAML frontmatter');
+      }
+
+      const [, frontmatterYaml, body] = match;
+
+      // Parse YAML frontmatter
+      const frontmatter = parseYaml(frontmatterYaml) as Record<string, unknown>;
+
+      // Extract required fields
+      const nameRaw = frontmatter['name'];
+      const descriptionRaw = frontmatter['description'];
+
+      if (nameRaw == null || nameRaw === '') {
+        throw new Error('Missing "name" in frontmatter');
+      }
+
+      if (descriptionRaw == null || descriptionRaw === '') {
+        throw new Error('Missing "description" in frontmatter');
+      }
+
+      // Convert to strings
+      const name = String(nameRaw);
+      const description = String(descriptionRaw);
+
+      // Extract optional fields
+      const allowedToolsRaw = frontmatter['allowedTools'] as
+        | unknown[]
+        | undefined;
+      let allowedTools: string[] | undefined;
+
+      if (allowedToolsRaw !== undefined) {
+        if (Array.isArray(allowedToolsRaw)) {
+          allowedTools = allowedToolsRaw.map(String);
+        } else {
+          throw new Error('"allowedTools" must be an array');
+        }
+      }
+
+      const config: SkillConfig = {
+        name,
+        description,
+        allowedTools,
+        level,
+        filePath,
+        body: body.trim(),
+      };
+
+      // Validate the parsed configuration
+      const validation = this.validateConfig(config);
+      if (!validation.isValid) {
+        throw new Error(`Validation failed: ${validation.errors.join(', ')}`);
+      }
+
+      return config;
+    } catch (error) {
+      const skillError = new SkillError(
+        `Failed to parse skill file: ${error instanceof Error ? error.message : 'Unknown error'}`,
+        SkillErrorCode.PARSE_ERROR,
+      );
+      this.parseErrors.set(filePath, skillError);
+      throw skillError;
+    }
+  }
+
+  /**
+   * Gets the base directory for skills at a specific level.
+   *
+   * @param level - Storage level
+   * @returns Absolute directory path
+   */
+  getSkillsBaseDir(level: SkillLevel): string {
+    const baseDir =
+      level === 'project'
+        ? path.join(
+            this.config.getProjectRoot(),
+            QWEN_CONFIG_DIR,
+            SKILLS_CONFIG_DIR,
+          )
+        : path.join(os.homedir(), QWEN_CONFIG_DIR, SKILLS_CONFIG_DIR);
+
+    return baseDir;
+  }
+
+  /**
+   * Lists skills at a specific level.
+   *
+   * @param level - Storage level to scan
+   * @returns Array of skill configurations
+   */
+  private async listSkillsAtLevel(level: SkillLevel): Promise<SkillConfig[]> {
+    const projectRoot = this.config.getProjectRoot();
+    const homeDir = os.homedir();
+    const isHomeDirectory = path.resolve(projectRoot) === path.resolve(homeDir);
+
+    // If project level is requested but project root is same as home directory,
+    // return empty array to avoid conflicts between project and global skills
+    if (level === 'project' && isHomeDirectory) {
+      return [];
+    }
+
+    const baseDir = this.getSkillsBaseDir(level);
+
+    try {
+      const entries = await fs.readdir(baseDir, { withFileTypes: true });
+      const skills: SkillConfig[] = [];
+
+      for (const entry of entries) {
+        // Only process directories (each skill is a directory)
+        if (!entry.isDirectory()) continue;
+
+        const skillDir = path.join(baseDir, entry.name);
+        const skillManifest = path.join(skillDir, SKILL_MANIFEST_FILE);
+
+        try {
+          // Check if SKILL.md exists
+          await fs.access(skillManifest);
+
+          const config = await this.parseSkillFileInternal(
+            skillManifest,
+            level,
+          );
+          skills.push(config);
+        } catch (error) {
+          // Skip directories without valid SKILL.md
+          if (error instanceof SkillError) {
+            // Parse error was already recorded
+            console.warn(
+              `Failed to parse skill at ${skillDir}: ${error.message}`,
+            );
+          }
+          continue;
+        }
+      }
+
+      return skills;
+    } catch (_error) {
+      // Directory doesn't exist or can't be read
+      return [];
+    }
+  }
+
+  /**
+   * Finds a skill by name at a specific level.
+   *
+   * @param name - Name of the skill to find
+   * @param level - Storage level to search
+   * @returns SkillConfig or null if not found
+   */
+  private async findSkillByNameAtLevel(
+    name: string,
+    level: SkillLevel,
+  ): Promise<SkillConfig | null> {
+    await this.ensureLevelCache(level);
+
+    const levelSkills = this.skillsCache?.get(level) || [];
+
+    // Find the skill with matching name
+    return levelSkills.find((skill) => skill.name === name) || null;
+  }
+
+  /**
+   * Ensures the cache is populated for a specific level without loading other levels.
+   */
+  private async ensureLevelCache(level: SkillLevel): Promise<void> {
+    if (!this.skillsCache) {
+      this.skillsCache = new Map<SkillLevel, SkillConfig[]>();
+    }
+
+    if (!this.skillsCache.has(level)) {
+      const levelSkills = await this.listSkillsAtLevel(level);
+      this.skillsCache.set(level, levelSkills);
+    }
+  }
+}
--- a/packages/core/src/skills/types.ts
+++ b/packages/core/src/skills/types.ts
@@ -0,0 +1,105 @@
+/**
+ * @license
+ * Copyright 2025 Qwen
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * Represents the storage level for a skill configuration.
+ * - 'project': Stored in `.qwen/skills/` within the project directory
+ * - 'user': Stored in `~/.qwen/skills/` in the user's home directory
+ */
+export type SkillLevel = 'project' | 'user';
+
+/**
+ * Core configuration for a skill as stored in SKILL.md files.
+ * Each skill directory contains a SKILL.md file with YAML frontmatter
+ * containing metadata, followed by markdown content describing the skill.
+ */
+export interface SkillConfig {
+  /** Unique name identifier for the skill */
+  name: string;
+
+  /** Human-readable description of what this skill provides */
+  description: string;
+
+  /**
+   * Optional list of tool names that this skill is allowed to use.
+   * For v1, this is informational only (no gating).
+   */
+  allowedTools?: string[];
+
+  /**
+   * Storage level - determines where the configuration file is stored
+   */
+  level: SkillLevel;
+
+  /**
+   * Absolute path to the skill directory containing SKILL.md
+   */
+  filePath: string;
+
+  /**
+   * The markdown body content from SKILL.md (after the frontmatter)
+   */
+  body: string;
+}
+
+/**
+ * Runtime configuration for a skill when it's being actively used.
+ * Extends SkillConfig with additional runtime-specific fields.
+ */
+export type SkillRuntimeConfig = SkillConfig;
+
+/**
+ * Result of a validation operation on a skill configuration.
+ */
+export interface SkillValidationResult {
+  /** Whether the configuration is valid */
+  isValid: boolean;
+
+  /** Array of error messages if validation failed */
+  errors: string[];
+
+  /** Array of warning messages (non-blocking issues) */
+  warnings: string[];
+}
+
+/**
+ * Options for listing skills.
+ */
+export interface ListSkillsOptions {
+  /** Filter by storage level */
+  level?: SkillLevel;
+
+  /** Force refresh from disk, bypassing cache. Defaults to false. */
+  force?: boolean;
+}
+
+/**
+ * Error thrown when a skill operation fails.
+ */
+export class SkillError extends Error {
+  constructor(
+    message: string,
+    readonly code: SkillErrorCode,
+    readonly skillName?: string,
+  ) {
+    super(message);
+    this.name = 'SkillError';
+  }
+}
+
+/**
+ * Error codes for skill operations.
+ */
+export const SkillErrorCode = {
+  NOT_FOUND: 'NOT_FOUND',
+  INVALID_CONFIG: 'INVALID_CONFIG',
+  INVALID_NAME: 'INVALID_NAME',
+  FILE_ERROR: 'FILE_ERROR',
+  PARSE_ERROR: 'PARSE_ERROR',
+} as const;
+
+export type SkillErrorCode =
+  (typeof SkillErrorCode)[keyof typeof SkillErrorCode];
--- a/packages/core/src/telemetry/constants.ts
+++ b/packages/core/src/telemetry/constants.ts
@@ -33,6 +33,7 @@ export const EVENT_MALFORMED_JSON_RESPONSE =
 export const EVENT_FILE_OPERATION = 'qwen-code.file_operation';
 export const EVENT_MODEL_SLASH_COMMAND = 'qwen-code.slash_command.model';
 export const EVENT_SUBAGENT_EXECUTION = 'qwen-code.subagent_execution';
+export const EVENT_SKILL_LAUNCH = 'qwen-code.skill_launch';
 export const EVENT_AUTH = 'qwen-code.auth';

 // Performance Events
--- a/packages/core/src/telemetry/index.ts
+++ b/packages/core/src/telemetry/index.ts
@@ -44,6 +44,7 @@ export {
  logRipgrepFallback,
  logNextSpeakerCheck,
  logAuth,
+  logSkillLaunch,
 } from './loggers.js';
 export type { SlashCommandEvent, ChatCompressionEvent } from './types.js';
 export {
@@ -63,6 +64,7 @@ export {
  RipgrepFallbackEvent,
  NextSpeakerCheckEvent,
  AuthEvent,
+  SkillLaunchEvent,
 } from './types.js';
 export { makeSlashCommandEvent, makeChatCompressionEvent } from './types.js';
 export type { TelemetryEvent } from './types.js';
--- a/packages/core/src/telemetry/loggers.test.ts
+++ b/packages/core/src/telemetry/loggers.test.ts
@@ -206,6 +206,8 @@ describe('loggers', () => {
          mcp_tools: undefined,
          mcp_tools_count: undefined,
          output_format: 'json',
+          skills: undefined,
+          subagents: undefined,
        },
      });
    });
--- a/packages/core/src/telemetry/loggers.ts
+++ b/packages/core/src/telemetry/loggers.ts
@@ -38,6 +38,7 @@ import {
  EVENT_MALFORMED_JSON_RESPONSE,
  EVENT_INVALID_CHUNK,
  EVENT_AUTH,
+  EVENT_SKILL_LAUNCH,
 } from './constants.js';
 import {
  recordApiErrorMetrics,
@@ -85,6 +86,7 @@ import type {
  MalformedJsonResponseEvent,
  InvalidChunkEvent,
  AuthEvent,
+  SkillLaunchEvent,
 } from './types.js';
 import type { UiEvent } from './uiTelemetry.js';
 import { uiTelemetryService } from './uiTelemetry.js';
@@ -127,6 +129,8 @@ export function logStartSession(
    mcp_tools: event.mcp_tools,
    mcp_tools_count: event.mcp_tools_count,
    output_format: event.output_format,
+    skills: event.skills,
+    subagents: event.subagents,
  };

  const logger = logs.getLogger(SERVICE_NAME);
@@ -869,3 +873,21 @@ export function logAuth(config: Config, event: AuthEvent): void {
  };
  logger.emit(logRecord);
 }
+
+export function logSkillLaunch(config: Config, event: SkillLaunchEvent): void {
+  if (!isTelemetrySdkInitialized()) return;
+
+  const attributes: LogAttributes = {
+    ...getCommonAttributes(config),
+    ...event,
+    'event.name': EVENT_SKILL_LAUNCH,
+    'event.timestamp': new Date().toISOString(),
+  };
+
+  const logger = logs.getLogger(SERVICE_NAME);
+  const logRecord: LogRecord = {
+    body: `Skill launch: ${event.skill_name}. Success: ${event.success}.`,
+    attributes,
+  };
+  logger.emit(logRecord);
+}
--- a/packages/core/src/telemetry/qwen-logger/qwen-logger.ts
+++ b/packages/core/src/telemetry/qwen-logger/qwen-logger.ts
@@ -38,6 +38,7 @@ import type {
  ModelSlashCommandEvent,
  ExtensionDisableEvent,
  AuthEvent,
+  SkillLaunchEvent,
  RipgrepFallbackEvent,
  EndSessionEvent,
 } from '../types.js';
@@ -388,6 +389,8 @@ export class QwenLogger {
        telemetry_enabled: event.telemetry_enabled,
        telemetry_log_user_prompts_enabled:
          event.telemetry_log_user_prompts_enabled,
+        skills: event.skills,
+        subagents: event.subagents,
      },
    });

@@ -824,6 +827,18 @@ export class QwenLogger {
    this.flushIfNeeded();
  }

+  logSkillLaunchEvent(event: SkillLaunchEvent): void {
+    const rumEvent = this.createActionEvent('misc', 'skill_launch', {
+      properties: {
+        skill_name: event.skill_name,
+        success: event.success ? 1 : 0,
+      },
+    });
+
+    this.enqueueLogEvent(rumEvent);
+    this.flushIfNeeded();
+  }
+
  logChatCompressionEvent(event: ChatCompressionEvent): void {
    const rumEvent = this.createActionEvent('misc', 'chat_compression', {
      properties: {
--- a/packages/core/src/telemetry/types.ts
+++ b/packages/core/src/telemetry/types.ts
@@ -18,6 +18,9 @@ import {
 import type { FileOperation } from './metrics.js';
 export { ToolCallDecision };
 import type { OutputFormat } from '../output/types.js';
+import { ToolNames } from '../tools/tool-names.js';
+import type { SkillTool } from '../tools/skill.js';
+import type { TaskTool } from '../tools/task.js';

 export interface BaseTelemetryEvent {
  'event.name': string;
@@ -47,6 +50,8 @@ export class StartSessionEvent implements BaseTelemetryEvent {
  mcp_tools_count?: number;
  mcp_tools?: string;
  output_format: OutputFormat;
+  skills?: string;
+  subagents?: string;

  constructor(config: Config) {
    const generatorConfig = config.getContentGeneratorConfig();
@@ -79,6 +84,7 @@ export class StartSessionEvent implements BaseTelemetryEvent {
      config.getFileFilteringRespectGitIgnore();
    this.mcp_servers_count = mcpServers ? Object.keys(mcpServers).length : 0;
    this.output_format = config.getOutputFormat();
+
    if (toolRegistry) {
      const mcpTools = toolRegistry
        .getAllTools()
@@ -87,6 +93,22 @@ export class StartSessionEvent implements BaseTelemetryEvent {
      this.mcp_tools = mcpTools
        .map((tool) => (tool as DiscoveredMCPTool).name)
        .join(',');
+
+      const skillTool = toolRegistry.getTool(ToolNames.SKILL) as
+        | SkillTool
+        | undefined;
+      const skillNames = skillTool?.getAvailableSkillNames?.();
+      if (skillNames && skillNames.length > 0) {
+        this.skills = skillNames.join(',');
+      }
+
+      const taskTool = toolRegistry.getTool(ToolNames.TASK) as
+        | TaskTool
+        | undefined;
+      const subagentNames = taskTool?.getAvailableSubagentNames?.();
+      if (subagentNames && subagentNames.length > 0) {
+        this.subagents = subagentNames.join(',');
+      }
    }
  }
 }
@@ -721,6 +743,20 @@ export class AuthEvent implements BaseTelemetryEvent {
  }
 }

+export class SkillLaunchEvent implements BaseTelemetryEvent {
+  'event.name': 'skill_launch';
+  'event.timestamp': string;
+  skill_name: string;
+  success: boolean;
+
+  constructor(skill_name: string, success: boolean) {
+    this['event.name'] = 'skill_launch';
+    this['event.timestamp'] = new Date().toISOString();
+    this.skill_name = skill_name;
+    this.success = success;
+  }
+}
+
 export type TelemetryEvent =
  | StartSessionEvent
  | EndSessionEvent
@@ -749,7 +785,8 @@ export type TelemetryEvent =
  | ExtensionUninstallEvent
  | ToolOutputTruncatedEvent
  | ModelSlashCommandEvent
-  | AuthEvent;
+  | AuthEvent
+  | SkillLaunchEvent;

 export class ExtensionDisableEvent implements BaseTelemetryEvent {
  'event.name': 'extension_disable';
--- a/packages/core/src/tools/ls.test.ts
+++ b/packages/core/src/tools/ls.test.ts
@@ -31,6 +31,8 @@ describe('LSTool', () => {
      tempSecondaryDir,
    ]);

+    const userSkillsBase = path.join(os.homedir(), '.qwen', 'skills');
+
    mockConfig = {
      getTargetDir: () => tempRootDir,
      getWorkspaceContext: () => mockWorkspaceContext,
@@ -39,6 +41,9 @@ describe('LSTool', () => {
        respectGitIgnore: true,
        respectQwenIgnore: true,
      }),
+      storage: {
+        getUserSkillsDir: () => userSkillsBase,
+      },
    } as unknown as Config;

    lsTool = new LSTool(mockConfig);
@@ -288,7 +293,7 @@ describe('LSTool', () => {
      };
      const invocation = lsTool.build(params);
      const description = invocation.getDescription();
-      const expected = path.relative(tempRootDir, params.path);
+      const expected = path.resolve(params.path);
      expect(description).toBe(expected);
    });
  });
--- a/packages/core/src/tools/ls.ts
+++ b/packages/core/src/tools/ls.ts
@@ -9,6 +9,7 @@ import path from 'node:path';
 import type { ToolInvocation, ToolResult } from './tools.js';
 import { BaseDeclarativeTool, BaseToolInvocation, Kind } from './tools.js';
 import { makeRelative, shortenPath } from '../utils/paths.js';
+import { isSubpath } from '../utils/paths.js';
 import type { Config } from '../config/config.js';
 import { DEFAULT_FILE_FILTERING_OPTIONS } from '../config/constants.js';
 import { ToolErrorType } from './tool-error.js';
@@ -311,8 +312,14 @@ export class LSTool extends BaseDeclarativeTool<LSToolParams, ToolResult> {
      return `Path must be absolute: ${params.path}`;
    }

+    const userSkillsBase = this.config.storage.getUserSkillsDir();
+    const isUnderUserSkills = isSubpath(userSkillsBase, params.path);
+
    const workspaceContext = this.config.getWorkspaceContext();
-    if (!workspaceContext.isPathWithinWorkspace(params.path)) {
+    if (
+      !workspaceContext.isPathWithinWorkspace(params.path) &&
+      !isUnderUserSkills
+    ) {
      const directories = workspaceContext.getDirectories();
      return `Path must be within one of the workspace directories: ${directories.join(
        ', ',
--- a/packages/core/src/tools/read-file.test.ts
+++ b/packages/core/src/tools/read-file.test.ts
@@ -40,6 +40,7 @@ describe('ReadFileTool', () => {
      getWorkspaceContext: () => createMockWorkspaceContext(tempRootDir),
      storage: {
        getProjectTempDir: () => path.join(tempRootDir, '.temp'),
+        getUserSkillsDir: () => path.join(os.homedir(), '.qwen', 'skills'),
      },
      getTruncateToolOutputThreshold: () => 2500,
      getTruncateToolOutputLines: () => 500,
--- a/packages/core/src/tools/read-file.ts
+++ b/packages/core/src/tools/read-file.ts
@@ -20,6 +20,7 @@ import { FileOperation } from '../telemetry/metrics.js';
 import { getProgrammingLanguage } from '../telemetry/telemetry-utils.js';
 import { logFileOperation } from '../telemetry/loggers.js';
 import { FileOperationEvent } from '../telemetry/types.js';
+import { isSubpath } from '../utils/paths.js';

 /**
 * Parameters for the ReadFile tool
@@ -183,15 +184,20 @@ export class ReadFileTool extends BaseDeclarativeTool<

    const workspaceContext = this.config.getWorkspaceContext();
    const projectTempDir = this.config.storage.getProjectTempDir();
+    const userSkillsDir = this.config.storage.getUserSkillsDir();
    const resolvedFilePath = path.resolve(filePath);
-    const resolvedProjectTempDir = path.resolve(projectTempDir);
-    const isWithinTempDir =
-      resolvedFilePath.startsWith(resolvedProjectTempDir + path.sep) ||
-      resolvedFilePath === resolvedProjectTempDir;
+    const isWithinTempDir = isSubpath(projectTempDir, resolvedFilePath);
+    const isWithinUserSkills = isSubpath(userSkillsDir, resolvedFilePath);

-    if (!workspaceContext.isPathWithinWorkspace(filePath) && !isWithinTempDir) {
+    if (
+      !workspaceContext.isPathWithinWorkspace(filePath) &&
+      !isWithinTempDir &&
+      !isWithinUserSkills
+    ) {
      const directories = workspaceContext.getDirectories();
-      return `File path must be within one of the workspace directories: ${directories.join(', ')} or within the project temp directory: ${projectTempDir}`;
+      return `File path must be within one of the workspace directories: ${directories.join(
+        ', ',
+      )} or within the project temp directory: ${projectTempDir}`;
    }
    if (params.offset !== undefined && params.offset < 0) {
      return 'Offset must be a non-negative number';
--- a/packages/core/src/tools/skill.test.ts
+++ b/packages/core/src/tools/skill.test.ts
@@ -0,0 +1,442 @@
+/**
+ * @license
+ * Copyright 2025 Qwen
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
+import { SkillTool, type SkillParams } from './skill.js';
+import type { PartListUnion } from '@google/genai';
+import type { ToolResultDisplay } from './tools.js';
+import type { Config } from '../config/config.js';
+import { SkillManager } from '../skills/skill-manager.js';
+import type { SkillConfig } from '../skills/types.js';
+import { partToString } from '../utils/partUtils.js';
+
+// Type for accessing protected methods in tests
+type SkillToolWithProtectedMethods = SkillTool & {
+  createInvocation: (params: SkillParams) => {
+    execute: (
+      signal?: AbortSignal,
+      updateOutput?: (output: ToolResultDisplay) => void,
+    ) => Promise<{
+      llmContent: PartListUnion;
+      returnDisplay: ToolResultDisplay;
+    }>;
+    getDescription: () => string;
+    shouldConfirmExecute: () => Promise<boolean>;
+  };
+};
+
+// Mock dependencies
+vi.mock('../skills/skill-manager.js');
+vi.mock('../telemetry/index.js', () => ({
+  logSkillLaunch: vi.fn(),
+  SkillLaunchEvent: class {
+    constructor(
+      public skill_name: string,
+      public success: boolean,
+    ) {}
+  },
+}));
+
+const MockedSkillManager = vi.mocked(SkillManager);
+
+describe('SkillTool', () => {
+  let config: Config;
+  let skillTool: SkillTool;
+  let mockSkillManager: SkillManager;
+  let changeListeners: Array<() => void>;
+
+  const mockSkills: SkillConfig[] = [
+    {
+      name: 'code-review',
+      description: 'Specialized skill for reviewing code quality',
+      level: 'project',
+      filePath: '/project/.qwen/skills/code-review/SKILL.md',
+      body: 'Review code for quality and best practices.',
+    },
+    {
+      name: 'testing',
+      description: 'Skill for writing and running tests',
+      level: 'user',
+      filePath: '/home/user/.qwen/skills/testing/SKILL.md',
+      body: 'Help write comprehensive tests.',
+      allowedTools: ['read_file', 'write_file', 'shell'],
+    },
+  ];
+
+  beforeEach(async () => {
+    // Setup fake timers
+    vi.useFakeTimers();
+
+    // Create mock config
+    config = {
+      getProjectRoot: vi.fn().mockReturnValue('/test/project'),
+      getSessionId: vi.fn().mockReturnValue('test-session-id'),
+      getSkillManager: vi.fn(),
+      getGeminiClient: vi.fn().mockReturnValue(undefined),
+    } as unknown as Config;
+
+    changeListeners = [];
+
+    // Setup SkillManager mock
+    mockSkillManager = {
+      listSkills: vi.fn().mockResolvedValue(mockSkills),
+      loadSkill: vi.fn(),
+      loadSkillForRuntime: vi.fn(),
+      addChangeListener: vi.fn((listener: () => void) => {
+        changeListeners.push(listener);
+        return () => {
+          const index = changeListeners.indexOf(listener);
+          if (index >= 0) {
+            changeListeners.splice(index, 1);
+          }
+        };
+      }),
+      getParseErrors: vi.fn().mockReturnValue(new Map()),
+    } as unknown as SkillManager;
+
+    MockedSkillManager.mockImplementation(() => mockSkillManager);
+
+    // Make config return the mock SkillManager
+    vi.mocked(config.getSkillManager).mockReturnValue(mockSkillManager);
+
+    // Create SkillTool instance
+    skillTool = new SkillTool(config);
+
+    // Allow async initialization to complete
+    await vi.runAllTimersAsync();
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+    vi.clearAllMocks();
+  });
+
+  describe('initialization', () => {
+    it('should initialize with correct name and properties', () => {
+      expect(skillTool.name).toBe('skill');
+      expect(skillTool.displayName).toBe('Skill');
+      expect(skillTool.kind).toBe('read');
+    });
+
+    it('should load available skills during initialization', () => {
+      expect(mockSkillManager.listSkills).toHaveBeenCalled();
+    });
+
+    it('should subscribe to skill manager changes', () => {
+      expect(mockSkillManager.addChangeListener).toHaveBeenCalledTimes(1);
+    });
+
+    it('should update description with available skills', () => {
+      expect(skillTool.description).toContain('code-review');
+      expect(skillTool.description).toContain(
+        'Specialized skill for reviewing code quality',
+      );
+      expect(skillTool.description).toContain('testing');
+      expect(skillTool.description).toContain(
+        'Skill for writing and running tests',
+      );
+    });
+
+    it('should handle empty skills list gracefully', async () => {
+      vi.mocked(mockSkillManager.listSkills).mockResolvedValue([]);
+
+      const emptySkillTool = new SkillTool(config);
+      await vi.runAllTimersAsync();
+
+      expect(emptySkillTool.description).toContain(
+        'No skills are currently configured',
+      );
+    });
+
+    it('should handle skill loading errors gracefully', async () => {
+      vi.mocked(mockSkillManager.listSkills).mockRejectedValue(
+        new Error('Loading failed'),
+      );
+
+      const consoleSpy = vi.spyOn(console, 'warn').mockImplementation(() => {});
+
+      new SkillTool(config);
+      await vi.runAllTimersAsync();
+
+      expect(consoleSpy).toHaveBeenCalledWith(
+        'Failed to load skills for Skills tool:',
+        expect.any(Error),
+      );
+      consoleSpy.mockRestore();
+    });
+  });
+
+  describe('schema generation', () => {
+    it('should expose static schema without dynamic enums', () => {
+      const schema = skillTool.schema;
+      const properties = schema.parametersJsonSchema as {
+        properties: {
+          skill: {
+            type: string;
+            description: string;
+            enum?: string[];
+          };
+        };
+      };
+      expect(properties.properties.skill.type).toBe('string');
+      expect(properties.properties.skill.description).toBe(
+        'The skill name (no arguments). E.g., "pdf" or "xlsx"',
+      );
+      expect(properties.properties.skill.enum).toBeUndefined();
+    });
+
+    it('should keep schema static even when no skills available', async () => {
+      vi.mocked(mockSkillManager.listSkills).mockResolvedValue([]);
+
+      const emptySkillTool = new SkillTool(config);
+      await vi.runAllTimersAsync();
+
+      const schema = emptySkillTool.schema;
+      const properties = schema.parametersJsonSchema as {
+        properties: {
+          skill: {
+            type: string;
+            description: string;
+            enum?: string[];
+          };
+        };
+      };
+      expect(properties.properties.skill.type).toBe('string');
+      expect(properties.properties.skill.description).toBe(
+        'The skill name (no arguments). E.g., "pdf" or "xlsx"',
+      );
+      expect(properties.properties.skill.enum).toBeUndefined();
+    });
+  });
+
+  describe('validateToolParams', () => {
+    it('should validate valid parameters', () => {
+      const result = skillTool.validateToolParams({ skill: 'code-review' });
+      expect(result).toBeNull();
+    });
+
+    it('should reject empty skill', () => {
+      const result = skillTool.validateToolParams({ skill: '' });
+      expect(result).toBe('Parameter "skill" must be a non-empty string.');
+    });
+
+    it('should reject non-existent skill', () => {
+      const result = skillTool.validateToolParams({
+        skill: 'non-existent',
+      });
+      expect(result).toBe(
+        'Skill "non-existent" not found. Available skills: code-review, testing',
+      );
+    });
+
+    it('should show appropriate message when no skills available', async () => {
+      vi.mocked(mockSkillManager.listSkills).mockResolvedValue([]);
+
+      const emptySkillTool = new SkillTool(config);
+      await vi.runAllTimersAsync();
+
+      const result = emptySkillTool.validateToolParams({
+        skill: 'non-existent',
+      });
+      expect(result).toBe(
+        'Skill "non-existent" not found. No skills are currently available.',
+      );
+    });
+  });
+
+  describe('refreshSkills', () => {
+    it('should refresh when change listener fires', async () => {
+      const newSkills: SkillConfig[] = [
+        {
+          name: 'new-skill',
+          description: 'A brand new skill',
+          level: 'project',
+          filePath: '/project/.qwen/skills/new-skill/SKILL.md',
+          body: 'New skill content.',
+        },
+      ];
+
+      vi.mocked(mockSkillManager.listSkills).mockResolvedValueOnce(newSkills);
+
+      const listener = changeListeners[0];
+      expect(listener).toBeDefined();
+
+      listener?.();
+      await vi.runAllTimersAsync();
+
+      expect(skillTool.description).toContain('new-skill');
+      expect(skillTool.description).toContain('A brand new skill');
+    });
+
+    it('should refresh available skills and update description', async () => {
+      const newSkills: SkillConfig[] = [
+        {
+          name: 'test-skill',
+          description: 'A test skill',
+          level: 'project',
+          filePath: '/project/.qwen/skills/test-skill/SKILL.md',
+          body: 'Test content.',
+        },
+      ];
+
+      vi.mocked(mockSkillManager.listSkills).mockResolvedValue(newSkills);
+
+      await skillTool.refreshSkills();
+
+      expect(skillTool.description).toContain('test-skill');
+      expect(skillTool.description).toContain('A test skill');
+    });
+  });
+
+  describe('SkillToolInvocation', () => {
+    const mockRuntimeConfig: SkillConfig = {
+      ...mockSkills[0],
+    };
+
+    beforeEach(() => {
+      vi.mocked(mockSkillManager.loadSkillForRuntime).mockResolvedValue(
+        mockRuntimeConfig,
+      );
+    });
+
+    it('should execute skill load successfully', async () => {
+      const params: SkillParams = {
+        skill: 'code-review',
+      };
+
+      const invocation = (
+        skillTool as SkillToolWithProtectedMethods
+      ).createInvocation(params);
+      const result = await invocation.execute();
+
+      expect(mockSkillManager.loadSkillForRuntime).toHaveBeenCalledWith(
+        'code-review',
+      );
+
+      const llmText = partToString(result.llmContent);
+      expect(llmText).toContain(
+        'Base directory for this skill: /project/.qwen/skills/code-review',
+      );
+      expect(llmText.trim()).toContain(
+        'Review code for quality and best practices.',
+      );
+
+      expect(result.returnDisplay).toBe('Launching skill: code-review');
+    });
+
+    it('should include allowedTools in result when present', async () => {
+      const skillWithTools: SkillConfig = {
+        ...mockSkills[1],
+      };
+      vi.mocked(mockSkillManager.loadSkillForRuntime).mockResolvedValue(
+        skillWithTools,
+      );
+
+      const params: SkillParams = {
+        skill: 'testing',
+      };
+
+      const invocation = (
+        skillTool as SkillToolWithProtectedMethods
+      ).createInvocation(params);
+      const result = await invocation.execute();
+
+      const llmText = partToString(result.llmContent);
+      expect(llmText).toContain('testing');
+      // Base description is omitted from llmContent; ensure body is present.
+      expect(llmText).toContain('Help write comprehensive tests.');
+
+      expect(result.returnDisplay).toBe('Launching skill: testing');
+    });
+
+    it('should handle skill not found error', async () => {
+      vi.mocked(mockSkillManager.loadSkillForRuntime).mockResolvedValue(null);
+
+      const params: SkillParams = {
+        skill: 'non-existent',
+      };
+
+      const invocation = (
+        skillTool as SkillToolWithProtectedMethods
+      ).createInvocation(params);
+      const result = await invocation.execute();
+
+      const llmText = partToString(result.llmContent);
+      expect(llmText).toContain('Skill "non-existent" not found');
+    });
+
+    it('should handle execution errors gracefully', async () => {
+      vi.mocked(mockSkillManager.loadSkillForRuntime).mockRejectedValue(
+        new Error('Loading failed'),
+      );
+
+      const consoleSpy = vi
+        .spyOn(console, 'error')
+        .mockImplementation(() => {});
+
+      const params: SkillParams = {
+        skill: 'code-review',
+      };
+
+      const invocation = (
+        skillTool as SkillToolWithProtectedMethods
+      ).createInvocation(params);
+      const result = await invocation.execute();
+
+      const llmText = partToString(result.llmContent);
+      expect(llmText).toContain('Failed to load skill');
+      expect(llmText).toContain('Loading failed');
+
+      consoleSpy.mockRestore();
+    });
+
+    it('should not require confirmation', async () => {
+      const params: SkillParams = {
+        skill: 'code-review',
+      };
+
+      const invocation = (
+        skillTool as SkillToolWithProtectedMethods
+      ).createInvocation(params);
+      const shouldConfirm = await invocation.shouldConfirmExecute();
+
+      expect(shouldConfirm).toBe(false);
+    });
+
+    it('should provide correct description', () => {
+      const params: SkillParams = {
+        skill: 'code-review',
+      };
+
+      const invocation = (
+        skillTool as SkillToolWithProtectedMethods
+      ).createInvocation(params);
+      const description = invocation.getDescription();
+
+      expect(description).toBe('Launching skill: "code-review"');
+    });
+
+    it('should handle skill without additional files', async () => {
+      vi.mocked(mockSkillManager.loadSkillForRuntime).mockResolvedValue(
+        mockSkills[0],
+      );
+
+      const params: SkillParams = {
+        skill: 'code-review',
+      };
+
+      const invocation = (
+        skillTool as SkillToolWithProtectedMethods
+      ).createInvocation(params);
+      const result = await invocation.execute();
+
+      const llmText = partToString(result.llmContent);
+      expect(llmText).not.toContain('## Additional Files');
+
+      expect(result.returnDisplay).toBe('Launching skill: code-review');
+    });
+  });
+});
--- a/packages/core/src/tools/skill.ts
+++ b/packages/core/src/tools/skill.ts
@@ -0,0 +1,264 @@
+/**
+ * @license
+ * Copyright 2025 Qwen
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { BaseDeclarativeTool, BaseToolInvocation, Kind } from './tools.js';
+import { ToolNames, ToolDisplayNames } from './tool-names.js';
+import type { ToolResult, ToolResultDisplay } from './tools.js';
+import type { Config } from '../config/config.js';
+import type { SkillManager } from '../skills/skill-manager.js';
+import type { SkillConfig } from '../skills/types.js';
+import { logSkillLaunch, SkillLaunchEvent } from '../telemetry/index.js';
+import path from 'path';
+
+export interface SkillParams {
+  skill: string;
+}
+
+/**
+ * Skill tool that enables the model to access skill definitions.
+ * The tool dynamically loads available skills and includes them in its description
+ * for the model to choose from.
+ */
+export class SkillTool extends BaseDeclarativeTool<SkillParams, ToolResult> {
+  static readonly Name: string = ToolNames.SKILL;
+
+  private skillManager: SkillManager;
+  private availableSkills: SkillConfig[] = [];
+
+  constructor(private readonly config: Config) {
+    // Initialize with a basic schema first
+    const initialSchema = {
+      type: 'object',
+      properties: {
+        skill: {
+          type: 'string',
+          description: 'The skill name (no arguments). E.g., "pdf" or "xlsx"',
+        },
+      },
+      required: ['skill'],
+      additionalProperties: false,
+      $schema: 'http://json-schema.org/draft-07/schema#',
+    };
+
+    super(
+      SkillTool.Name,
+      ToolDisplayNames.SKILL,
+      'Execute a skill within the main conversation. Loading available skills...', // Initial description
+      Kind.Read,
+      initialSchema,
+      true, // isOutputMarkdown
+      false, // canUpdateOutput
+    );
+
+    this.skillManager = config.getSkillManager();
+    this.skillManager.addChangeListener(() => {
+      void this.refreshSkills();
+    });
+
+    // Initialize the tool asynchronously
+    this.refreshSkills();
+  }
+
+  /**
+   * Asynchronously initializes the tool by loading available skills
+   * and updating the description and schema.
+   */
+  async refreshSkills(): Promise<void> {
+    try {
+      this.availableSkills = await this.skillManager.listSkills();
+      this.updateDescriptionAndSchema();
+    } catch (error) {
+      console.warn('Failed to load skills for Skills tool:', error);
+      this.availableSkills = [];
+      this.updateDescriptionAndSchema();
+    } finally {
+      // Update the client with the new tools
+      const geminiClient = this.config.getGeminiClient();
+      if (geminiClient && geminiClient.isInitialized()) {
+        await geminiClient.setTools();
+      }
+    }
+  }
+
+  /**
+   * Updates the tool's description and schema based on available skills.
+   */
+  private updateDescriptionAndSchema(): void {
+    let skillDescriptions = '';
+    if (this.availableSkills.length === 0) {
+      skillDescriptions =
+        'No skills are currently configured. Skills can be created by adding directories with SKILL.md files to .qwen/skills/ or ~/.qwen/skills/.';
+    } else {
+      skillDescriptions = this.availableSkills
+        .map(
+          (skill) => `<skill>
+<name>
+${skill.name}
+</name>
+<description>
+${skill.description} (${skill.level})
+</description>
+<location>
+${skill.level}
+</location>
+</skill>`,
+        )
+        .join('\n');
+    }
+
+    const baseDescription = `Execute a skill within the main conversation
+
+<skills_instructions>
+When users ask you to perform tasks, check if any of the available skills below can help complete the task more effectively. Skills provide specialized capabilities and domain knowledge.
+
+How to invoke:
+- Use this tool with the skill name only (no arguments)
+- Examples:
+  - \`skill: "pdf"\` - invoke the pdf skill
+  - \`skill: "xlsx"\` - invoke the xlsx skill
+  - \`skill: "ms-office-suite:pdf"\` - invoke using fully qualified name
+
+Important:
+- When a skill is relevant, you must invoke this tool IMMEDIATELY as your first action
+- NEVER just announce or mention a skill in your text response without actually calling this tool
+- This is a BLOCKING REQUIREMENT: invoke the relevant Skill tool BEFORE generating any other response about the task
+- Only use skills listed in <available_skills> below
+- Do not invoke a skill that is already running
+- Do not use this tool for built-in CLI commands (like /help, /clear, etc.)
+</skills_instructions>
+
+<available_skills>
+${skillDescriptions}
+</available_skills>
+`;
+    // Update description using object property assignment
+    (this as { description: string }).description = baseDescription;
+  }
+
+  override validateToolParams(params: SkillParams): string | null {
+    // Validate required fields
+    if (
+      !params.skill ||
+      typeof params.skill !== 'string' ||
+      params.skill.trim() === ''
+    ) {
+      return 'Parameter "skill" must be a non-empty string.';
+    }
+
+    // Validate that the skill exists
+    const skillExists = this.availableSkills.some(
+      (skill) => skill.name === params.skill,
+    );
+
+    if (!skillExists) {
+      const availableNames = this.availableSkills.map((s) => s.name);
+      if (availableNames.length === 0) {
+        return `Skill "${params.skill}" not found. No skills are currently available.`;
+      }
+      return `Skill "${params.skill}" not found. Available skills: ${availableNames.join(', ')}`;
+    }
+
+    return null;
+  }
+
+  protected createInvocation(params: SkillParams) {
+    return new SkillToolInvocation(this.config, this.skillManager, params);
+  }
+
+  getAvailableSkillNames(): string[] {
+    return this.availableSkills.map((skill) => skill.name);
+  }
+}
+
+class SkillToolInvocation extends BaseToolInvocation<SkillParams, ToolResult> {
+  constructor(
+    private readonly config: Config,
+    private readonly skillManager: SkillManager,
+    params: SkillParams,
+  ) {
+    super(params);
+  }
+
+  getDescription(): string {
+    return `Launching skill: "${this.params.skill}"`;
+  }
+
+  override async shouldConfirmExecute(): Promise<false> {
+    // Skill loading is a read-only operation, no confirmation needed
+    return false;
+  }
+
+  async execute(
+    _signal?: AbortSignal,
+    _updateOutput?: (output: ToolResultDisplay) => void,
+  ): Promise<ToolResult> {
+    try {
+      // Load the skill with runtime config (includes additional files)
+      const skill = await this.skillManager.loadSkillForRuntime(
+        this.params.skill,
+      );
+
+      if (!skill) {
+        // Log failed skill launch
+        logSkillLaunch(
+          this.config,
+          new SkillLaunchEvent(this.params.skill, false),
+        );
+
+        // Get parse errors if any
+        const parseErrors = this.skillManager.getParseErrors();
+        const errorMessages: string[] = [];
+
+        for (const [filePath, error] of parseErrors) {
+          if (filePath.includes(this.params.skill)) {
+            errorMessages.push(`Parse error at ${filePath}: ${error.message}`);
+          }
+        }
+
+        const errorDetail =
+          errorMessages.length > 0
+            ? `\nErrors:\n${errorMessages.join('\n')}`
+            : '';
+
+        return {
+          llmContent: `Skill "${this.params.skill}" not found.${errorDetail}`,
+          returnDisplay: `Skill "${this.params.skill}" not found.${errorDetail}`,
+        };
+      }
+
+      // Log successful skill launch
+      logSkillLaunch(
+        this.config,
+        new SkillLaunchEvent(this.params.skill, true),
+      );
+
+      const baseDir = path.dirname(skill.filePath);
+
+      // Build markdown content for LLM (show base dir, then body)
+      const llmContent = `Base directory for this skill: ${baseDir}\n\n${skill.body}\n`;
+
+      return {
+        llmContent: [{ text: llmContent }],
+        returnDisplay: `Launching skill: ${skill.name}`,
+      };
+    } catch (error) {
+      const errorMessage =
+        error instanceof Error ? error.message : String(error);
+      console.error(`[SkillsTool] Error launching skill: ${errorMessage}`);
+
+      // Log failed skill launch
+      logSkillLaunch(
+        this.config,
+        new SkillLaunchEvent(this.params.skill, false),
+      );
+
+      return {
+        llmContent: `Failed to load skill "${this.params.skill}": ${errorMessage}`,
+        returnDisplay: `Failed to load skill "${this.params.skill}": ${errorMessage}`,
+      };
+    }
+  }
+}
--- a/packages/core/src/tools/task.ts
+++ b/packages/core/src/tools/task.ts
@@ -252,6 +252,10 @@ assistant: "I'm going to use the Task tool to launch the with the greeting-respo
  protected createInvocation(params: TaskParams) {
    return new TaskToolInvocation(this.config, this.subagentManager, params);
  }
+
+  getAvailableSubagentNames(): string[] {
+    return this.availableSubagents.map((subagent) => subagent.name);
+  }
 }

 class TaskToolInvocation extends BaseToolInvocation<TaskParams, ToolResult> {
--- a/packages/core/src/tools/tool-names.ts
+++ b/packages/core/src/tools/tool-names.ts
@@ -20,6 +20,7 @@ export const ToolNames = {
  TODO_WRITE: 'todo_write',
  MEMORY: 'save_memory',
  TASK: 'task',
+  SKILL: 'skill',
  EXIT_PLAN_MODE: 'exit_plan_mode',
  WEB_FETCH: 'web_fetch',
  WEB_SEARCH: 'web_search',
@@ -42,6 +43,7 @@ export const ToolDisplayNames = {
  TODO_WRITE: 'TodoWrite',
  MEMORY: 'SaveMemory',
  TASK: 'Task',
+  SKILL: 'Skill',
  EXIT_PLAN_MODE: 'ExitPlanMode',
  WEB_FETCH: 'WebFetch',
  WEB_SEARCH: 'WebSearch',
--- a/packages/core/src/utils/paths.ts
+++ b/packages/core/src/utils/paths.ts
@@ -120,6 +120,10 @@ export function makeRelative(
  const resolvedTargetPath = path.resolve(targetPath);
  const resolvedRootDirectory = path.resolve(rootDirectory);

+  if (!isSubpath(resolvedRootDirectory, resolvedTargetPath)) {
+    return resolvedTargetPath;
+  }
+
  const relativePath = path.relative(resolvedRootDirectory, resolvedTargetPath);

  // If the paths are the same, path.relative returns '', return '.' instead