Agent skill · writing content · obra
writing-skills
Use when creating new skills, editing existing skills, or verifying skills work before deployment
Why this skill is useful
Provides structured documentation patterns and test-driven development principles for creating reusable skills that the AI wouldn't reliably generate on its own.
What it needs
About 11k tokens when loaded. Last updated 2026-08-07. 268,212 stars on the source repository.
What this skill does
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 or 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. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills obra/writing-skills