skill-developer

これはレビュー時に保存された抜粋です。完全で最新の内容は外部ソースを確認してください。

---
name: skill-developer
description: Create and manage Claude Code skills following Anthropic best practices. Use when creating new skills, modifying skill-rules.json, understanding trigger patterns, working with hooks, debugging skill activation, or implementing progressive disclosure. Covers skill structure, YAML frontmatter, trigger types (keywords, intent patterns, file paths, content patterns), enforcement levels (block, suggest, warn), hook mechanisms (UserPromptSubmit, PreToolUse), session tracking, and the 500-line rule.
---

# Skill Developer Guide

## Purpose

Comprehensive guide for creating and managing skills in Claude Code with auto-activation system, following Anthropic's official best practices including the 500-line rule and progressive disclosure pattern.

## When to Use This Skill

Automatically activates when you mention:
- Creating or adding skills
- Modifying skill triggers or rules
- Understanding how skill activation works
- Debugging skill activation issues
- Working with skill-rules.json
- Hook system mechanics
- Claude Code best practices
- Progressive disclosure
- YAML frontmatter
- 500-line rule

---

## System Overview

### Two-Hook Architecture

**1. UserPromptSubmit Hook** (Proactive Suggestions)
- **File**: `.claude/hooks/skill-activation-prompt.ts`
- **Trigger**: BEFORE Claude sees user's prompt
- **Purpose**: Suggest relevant skills based on keywords + intent patterns
- **Method**: Injects formatted reminder as context (stdout → Claude's input)
- **Use Cases**: Topic-based skills, implicit work detection

**2. Stop Hook - Error Handling Reminder** (Gentle Reminders)
- **File**: `.claude/hooks/error-handling-reminder.ts`
- **Trigger**: AFTER Claude finishes responding
- **Purpose**: Gentle reminder to self-assess error handling in code written
- **Method**: Analyzes edited files for risky patterns, displays reminder if needed
- **Use Cases**: Error handling awareness without blocking friction

**Philosophy Change (2025-10-27):** We moved away from blocking PreToolUse for Sentry/error handling. Instead, use gentle post-response reminders that don't block workflow but maintain code quality awareness.

### Configuration File

**Location**: `.claude/skills/skill-rules.json`

Defines:
- All skills and their trigger conditions
- Enforcement levels (block, suggest, warn)
- File path patterns (glob)
- Content detection patterns (regex)
- Skip conditions (session tracking, file markers, env vars)

---

## Skill Types

### 1. Guardrail Skills

**Purpose:** Enforce critical best practices that prevent errors

**Characteristics:**
- Type: `"guardrail"`
- Enforcement: `"block"`
- Priority: `"critical"` or `"high"`
- Block file edits until skill used
- Prevent common mistakes (column names, critical errors)
- Session-aware (don't repeat nag in same session)

**Examples:**
- `database-verification` - Verify table/column names before Prisma queries
- `frontend-dev-guidelines` - Enforce React/TypeScript patterns

**When to Use:**
- Mistakes that cause runtime errors
- Data integrity concerns
- Critical compatibility issues

### 2. Domain Skills

**Purpose:** Provide comprehensive guidance for specific areas

**Characteristics:**
- Type: `"domain"`
- Enforcement: `"suggest"`
- Priority: `"high"` or `"medium"`
- Advisory, not mandatory
- Topic or domain-specific
- Comprehensive documentation

**Examples:**
- `backend-dev-guidelines` - Node.js/Express/TypeScript patterns
- `frontend-dev-guidelines` - React/TypeScript best practices
- `error-tracking` - Sentry integration guidance

**When to Use:**
- Complex systems requiring deep knowledge
- Best practices documentation
- Architectural patterns
- How-to guides

---

## Quick Start: Creating a New Skill

### Step 1: Create Skill File

**Location:** `.claude/skills/{skill-name}/SKILL.md`

**Template:**
```markdown
---
name: my-new-skill
description: Brief description including keywords that trigger this skill. Mention topics, file types, and use cases. Be explici