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+---
+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.