skill-developer

# 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 ...