writing-skills

--- name: writing-skills description: Use when creating new skills, editing existing skills, or verifying skills work before deployment --- # Writing Skills ## Overview **Writing skills IS Test-Driven Development applied to process documentation.** **Personal skills live in agent-specific directories (`~/.claude/skills` for Claude Code, `~/.agents/skills/` for Codex)** You write test cases (pressure scenarios with subagents), watch them fail (baseline behavior), write the skill (documentation), watch tests pass (agents comply), and refactor (close loopholes). **Core principle:** If you didn't watch an agent fail without the skill, you don't know if the skill teaches the right thing. **REQUIRED BACKGROUND:** You MUST understand superpowers:test-driven-development before using this skill. That skill defines the fundamental RED-GREEN-REFACTOR cycle. This skill adapts TDD to documentation. **Official guidance:** For Anthropic's official skill authoring best practices, see anthropic-best-practices.md. This document provides additional patterns and guidelines that complement the TDD-focused approach in this skill. ## What is a Skill? A **skill** is a reference guide for proven techniques, patterns, or tools. Skills help future Claude instances find and apply effective approaches. **Skills are:** Reusable techniques, patterns, tools, reference guides **Skills are NOT:** Narratives about how you solved a problem once ## TDD Mapping for Skills | TDD Concept | Skill Creation | |-------------|----------------| | **Test case** | Pressure scenario with subagent | | **Production code** | Skill document (SKILL.md) | | **Test fails (RED)** | Agent violates rule without skill (baseline) | | **Test passes (GREEN)** | Agent complies with skill present | | **Refactor** | Close loopholes while maintaining compliance | | **Write test first** | Run baseline scenario BEFORE writing skill | | **Watch it fail** | Document exact rationalizations agent uses | | **Minimal code** [... prompt truncated for preview ...]