writing-skills

# Writing Skills ## Overview **Writing skills IS Test-Driven Development applied to process documentation.** **Personal skills live in your runtime's skills directory** (`~/.claude/skills/` on Claude Code) — see [codex-tools.md](../using-superpowers/references/codex-tools.md) or [gemini-tools.md](../using-superpowers/references/gemini-tools.md) for the path on those runtimes. Codex, Copilot CLI, and Gemini CLI all also recognize `~/.agents/skills/` as a cross-runtime alias. 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 agents find and apply effective approaches. **Skills are:** Reusable techniques, patterns, tools, reference guides **Skills are NOT:** Narrat...