Chapter 10: Agent Skills

What are Agent Skills?

Agent Skills are predefined specialized task workflows, like "macros" or "shortcuts," enabling Claude to quickly execute common development tasks.

Core Features:

• 🚀 Quick Execution: Complete complex tasks with one command
• 🎯 Specialized: Optimized for specific scenarios
• 🔄 Reusable: Standardized workflows
• 📝 Customizable: Support custom Skills

---

Built-in Skills

/commit - Code Commit

Purpose: Intelligently create Git commits

Usage:

10.2 内置技能

You: /commit

Claude: I'll create a commit with your changes.

[Analyzing changes...]
Modified files:
  - src/app.js (authentication logic)
  - src/utils.js (helper functions)
  - tests/app.test.js (new tests)

[Creating commit...]
$ git add src/app.js src/utils.js tests/app.test.js
$ git commit -m "feat: implement user authentication

- Add JWT token generation
- Create login/logout endpoints
- Add authentication middleware
- Include comprehensive tests

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>"

✓ Commit created: abc123def

/review-pr - PR Review

Purpose: Review Pull Requests

Usage:

You: /review-pr 123

Claude: Reviewing PR #123...

📋 PR Analysis
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Title: Add user profile feature
Changes: +450 -120 across 8 files

✅ Strengths:
- Good test coverage (87%)
- Follows project conventions
- Clear commit messages

⚠ Issues Found:
1. Security: SQL injection risk (user.js:45)
2. Performance: N+1 query (profile.js:78)
3. Style: Missing error handling (api.js:12)

💡 Suggestions:
- Use parameterized queries
- Add database indexing
- Implement error middleware
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

/feature-dev - Feature Development

Purpose: Guide complete feature development

Usage:

You: /feature-dev "comment system"

Claude: Starting feature development workflow...

[Phase 1: Understanding Requirements]
Please answer these questions:
1. Should comments support replies/threading?
2. Need moderation features?
3. Support markdown formatting?

You: 1. Yes 2. Yes 3. Yes

[Phase 2: Exploring Codebase]
Analyzing existing patterns...
✓ Found similar feature in forum module

[Phase 3: Architecture Design]
Creating architecture blueprint...
✓ Database schema designed
✓ API endpoints planned
✓ Frontend components outlined

[Phase 4: Implementation]
Creating files...
✓ models/Comment.js
✓ routes/comments.js
✓ components/CommentSection.jsx
✓ middleware/moderation.js

[Phase 5: Testing]
Generating tests...
✓ 24 tests created and passing

[Phase 6: Documentation]
✓ API documentation generated
✓ Component usage guide created

Feature development complete! 🎉

/code-review - Code Review

Purpose: Review code quality

Usage:

You: /code-review src/api.js

Claude: Reviewing src/api.js...

🔍 Code Review Report
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
File: src/api.js (250 lines)

✅ Good Practices:
- Clear function names
- Consistent error handling
- Good separation of concerns

❌ Issues:
1. [High] Security: No input validation (lines 45-50)
2. [Medium] Performance: Inefficient loop (line 78)
3. [Low] Style: Magic numbers (line 120)

📝 Recommendations:
- Add input validation middleware
- Use Array.filter instead of manual loop
- Extract constants to config file

Overall Score: 7/10
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

---

Custom Skills

Create Custom Skill

Create skill definition in ~/.config/claude-code/skills/:

10.3 自定义技能

# deploy.skill.yaml
name: deploy
description: Deploy application to production
version: 1.0.0

steps:
  - name: Run Tests
    action: bash
    command: npm test

  - name: Build Production
    action: bash
    command: npm run build

  - name: Deploy
    action: bash
    command: ./deploy.sh production

  - name: Verify Deployment
    action: bash
    command: curl https://myapp.com/health

prompts:
  - question: "Which environment?"
    options: ["staging", "production"]
    default: "staging"

Use Custom Skill

You: /deploy

Claude: Running deployment skill...

Which environment?
  › staging
    production

You: production

[Step 1/4] Running tests...
✓ All tests passed

[Step 2/4] Building production...
✓ Build complete

[Step 3/4] Deploying...
✓ Deployed successfully

[Step 4/4] Verifying deployment...
✓ Health check passed

Deployment complete! 🚀

---

Skill Development Guide

Skill Configuration Structure

name: skill-name
description: Skill description
version: 1.0.0
author: Your Name

# Prerequisites
prerequisites:
  - npm
  - git

# Parameter definitions
parameters:
  - name: environment
    type: string
    required: true
    options: ["dev", "staging", "prod"]

# Step definitions
steps:
  - name: Step Name
    action: bash | read | write | edit
    command: command to run
    on_error: continue | abort
    condition: expression

# User prompts
prompts:
  - question: Question text
    variable: var_name
    options: [option1, option2]
    default: option1

# Outputs
outputs:
  - name: result
    description: Output description

Advanced Example

name: database-backup
description: Backup database with verification
version: 1.0.0

parameters:
  - name: db_name
    type: string
    required: true

  - name: backup_type
    type: string
    options: ["full", "incremental"]
    default: "full"

steps:
  - name: Create Backup Directory
    action: bash
    command: mkdir -p ./backups/$(date +%Y%m%d)

  - name: Dump Database
    action: bash
    command: |
      pg_dump $DB_NAME > ./backups/$(date +%Y%m%d)/${db_name}.sql
    env:
      DB_NAME: "{{db_name}}"

  - name: Compress Backup
    action: bash
    command: gzip ./backups/$(date +%Y%m%d)/${db_name}.sql

  - name: Verify Backup
    action: bash
    command: |
      if [ -f "./backups/$(date +%Y%m%d)/${db_name}.sql.gz" ]; then
        echo "Backup verified"
      else
        exit 1
      fi
    on_error: abort

  - name: Upload to S3
    action: bash
    command: |
      aws s3 cp ./backups/$(date +%Y%m%d)/${db_name}.sql.gz \
        s3://my-backups/$(date +%Y%m%d)/
    condition: "{{backup_type}} == 'full'"

notifications:
  - type: success
    message: "Backup completed: {{db_name}}"
  - type: error
    message: "Backup failed for {{db_name}}"

Summary

In this chapter, we learned:

• ✅ Agent Skills concept
• ✅ Built-in skill usage (/commit, /review-pr, /feature-dev, etc.)
• ✅ Create custom Skills
• ✅ Skill development guide and advanced examples

Key Takeaways:

• Skills standardize common workflows
• Can create and share custom Skills
• Support complex steps and conditional logic
• Improve development efficiency