This file is byte-identical to the first copy the registry indexed, one of 3 indexed copies. Same content hash, so the same checks give both the same grade.
writing-skills from chinkan/rustfox is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
Use when creating new skills, editing existing skills, or verifying skills work before deployment.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# 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.
…
The line at the top of this page pins the label git:20260408.ae338c2, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
A 17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.
pass: Frontmatter block present
pass: Frontmatter declares a name
pass: Frontmatter declares a description
pass: Size between 200 bytes and 200 KB (22624 bytes)
pass: No zero-width or bidi control characters
pass: No instruction hidden inside an HTML comment
pass: No link to an exfiltration or paste host
pass: No credential-shaped string
pass: No instruction to send local credentials anywhere
pass: No text hidden with inline styles
pass: No prompt-injection phrasing
pass: No curl or wget piped into a shell
pass: No recursive delete of root, home or parent
pass: No instruction to read or print local credentials
pass: No base64 blob over 200 characters
pass: No link to a raw IP address
pass: No script tag
Source
GitHub
chinkan/rustfox · 11 stars · license MIT · pushed 2026-11-03 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_wjahjtm5oihiwxfe
GET https://markdownregistry.com/api/v1/resolve?ref=chinkan/rustfox/writing-skills
GET https://markdownregistry.com/api/v1/blob/38ba648975ae6ba512d6695676f146163db61a496b867f716f4bdfb0ee3aca3e
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
chinkan/rustfox · .agents/skills/brainstorming/SKILL.md · You MUST use this before any creative work - creating features, building components, adding functionality, or modifying…
chinkan/rustfox · .agents/skills/cavecrew/SKILL.md · Decision guide for delegating to caveman-style subagents. Tells the main thread WHEN to spawn `cavecrew-investigator`…
chinkan/rustfox · .agents/skills/caveman-compress/SKILL.md · Compress natural language memory files (CLAUDE.md, todos, preferences) into caveman format to save input tokens…
chinkan/rustfox · .agents/skills/caveman-help/SKILL.md · Quick-reference card for all caveman modes, skills, and commands. One-shot display, not a persistent mode. Trigger…
chinkan/rustfox · .agents/skills/caveman-review/SKILL.md · Ultra-compressed code review comments. Cuts noise from PR feedback while preserving the actionable signal. Each comment…
chinkan/rustfox · .agents/skills/caveman-stats/SKILL.md · Show real token usage and estimated savings for the current session. Reads directly from the Claude Code session log —…
chinkan/rustfox · .agents/skills/caveman/SKILL.md · Ultra-compressed communication mode. Cuts output tokens 65% (measured) by speaking like caveman while keeping full…
chinkan/rustfox · .agents/skills/code-review/SKILL.md · Review the changes since a fixed point (commit, branch, tag, or merge-base) along two axes: Standards (does the code…
chinkan/rustfox · .agents/skills/codebase-design/SKILL.md · Shared vocabulary for designing deep modules. Use when the user wants to design or improve a module's interface, find…
chinkan/rustfox · .agents/skills/design-an-interface/SKILL.md · Generate multiple radically different interface designs for a module using parallel sub-agents. Use when user wants to…
a5c-ai/babysitter · library/methodologies/superpowers/skills/writing-skills/SKILL.md · Use when creating new skills, editing existing skills, or verifying skills work before deployment.
coco-research/coco · skills/writing-skills/SKILL.md · Use when creating new skills, editing existing skills, or verifying skills work before deployment
xu123-bob/baize · agent/skills/superpowers/5.1.0/skills/writing-skills/SKILL.md · Use when creating new skills, editing existing skills, or verifying skills work before deployment
jamditis/claude-skills-journalism · superjawn/skills/writing-skills/SKILL.md · Use when creating new skills, editing existing skills, or verifying skills work before deployment
ibrahim-3d/orchestrator-supaconductor · skills/writing-skills/SKILL.md · Use when creating new skills, editing existing skills, or verifying skills work before deployment
