writing-skills
The library’s self-growth skill: create or edit a skill so future agents can find and apply a proven technique → artifact-skill-doc. Its central claim is that writing skills IS Test-Driven Development applied to process documentation (pattern-test-driven-development via sp-test-driven-development as required background).
The Iron Law (same as TDD): “NO SKILL WITHOUT A FAILING TEST FIRST.” The “test” is a pressure scenario run against a subagent: watch it fail (baseline — the agent rationalizes without the skill), write the skill addressing those exact rationalizations, watch it pass (the agent complies), then refactor to close loopholes. Applies to new skills and edits.
Most of the skill is Skill Discovery Optimization: the description field must state only when to use the skill (never summarize its workflow — a summarized workflow becomes a shortcut agents take instead of reading the body); keyword coverage, active-voice gerund naming, aggressive token-budget targets, cross-references via **REQUIRED SUB-SKILL:** markers (never @-links, which force-load and burn context), and rules for when a flowchart earns its place. Companion refs: anthropic-best-practices.md, persuasion-principles.md, testing-skills-with-subagents.md.
This is capability compounding — a successful run hardens into a permanent, reusable skill so the lifecycle compounds (pattern-knowledge-compounding) — the direct counterpart to gstack-skillify (which codifies a successful scrape into a permanent browser-skill). It sits in stage-learn as the agent-capability flavor: the product is not shipped software but reusable knowledge future agents read. Superpowers touches stage-learn only through this skill (no retrospective / solution-corpus capability).
See Also
- sp-test-driven-development — the required background; this skill is TDD applied to documentation.
- sp-using-superpowers — the bootstrap that discovers and enforces the skills this one writes.
- gstack-skillify — the counterpart capability-compounding skill (codify a proven run into a permanent skill).
- artifact-skill-doc — the SKILL.md it produces.
- pattern-knowledge-compounding · pattern-test-driven-development — the techniques applied.
- stage-learn — the canonical stage this implements.