Writing Skills
Purpose
Writing skills is TDD applied to process documentation: RED → GREEN → REFACTOR. If you didn’t watch a baseline failure, you don’t know what to fix.
Required background: superpowers:test-driven-development.
Official model (progressive disclosure)
- •Metadata (always loaded): YAML
name,description. - •Instructions (on trigger):
SKILL.mdbody. - •Resources/scripts (as needed): linked files + tools.
What to include in a skill
- •Overview: 1–2 sentences with the core principle.
- •When to use: triggers/symptoms + when NOT to use.
- •Core pattern: steps or before/after pattern.
- •Quick reference: concise table or bullets.
- •Examples: one excellent, runnable example.
- •Common mistakes: failure → fix.
Frontmatter rules (standard)
- •
name: lowercase letters/numbers/hyphens only, max 64 chars, no reserved words. - •
description: third-person, what + when, max 1024 chars. Start with “Use when…”. - •Avoid workflow summaries in
description(they become shortcuts and skip the body).
Claude Code extensions (optional): disable-model-invocation, allowed-tools, context, agent, etc. Use only when targeting Claude Code.
TDD loop for skills (essentials)
- •RED: run pressure scenario without the skill; capture rationalizations verbatim.
- •GREEN: write minimal skill to block those rationalizations.
- •REFACTOR: add explicit counters and retest until compliant.
Detailed testing format: see testing-skills-with-subagents.md.
Search optimization (CSO)
- •Description must include what + when with concrete triggers.
- •Use likely search terms: error strings, symptoms, tool names.
- •Prefer verb-first names (e.g.,
creating-skills,debugging-with-logs).
Anti-patterns (avoid)
- •Narratives or one-off stories.
- •Multi-language examples.
- •Deep reference chains (keep all references one hop from
SKILL.md). - •Time-sensitive instructions.
- •Vague names or descriptions.
Quick creation checklist
- • Run baseline scenario (RED) and record failures
- • Write skill addressing those exact failures (GREEN)
- • Add explicit counters for new rationalizations (REFACTOR)
- • Frontmatter: valid
name,description(what + when) - • One excellent example, one quick reference
- • Verify under pressure (retest)
Additional references
- •
anthropic-best-practices.md— concise official guidance - •
testing-skills-with-subagents.md— scenario templates and pressure testing - •
persuasion-principles.md— use only for discipline skills