# Use Skill Create > Use when creating new skills, editing existing skills, or verifying skills work before deployment - Skill: `tomevault-io/use-skill-create` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/use-skill-create` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/use-skill-create/raw - Safety review: pending (external: skill-scanner PASS, skillspector CAUTION) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/use-skill-create --- **Writing skills IS Test-Driven Development applied to process documentation.** 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 autonome:use-tdd before using this skill. # What is a Skill? A **skill** is a reference guide for proven techniques, patterns, or tools. **Skills are:** Reusable techniques, patterns, tools, reference guides **Skills are NOT:** Narratives about how you solved a problem once # When to Create a Skill **Create when:** - Technique wasn't intuitively obvious to you - You'd reference this again across projects - Pattern applies broadly (not project-specific) - Others would benefit **Don't create for:** - One-off solutions - Standard practices well-documented elsewhere - Project-specific conventions (put in CLAUDE.md) - Mechanical constraints (automate with regex/validation) # The Iron Law (Same as TDD) ``` NO SKILL WITHOUT A FAILING TEST FIRST ``` This applies to NEW skills AND EDITS to existing skills. Write skill before testing? Delete it. Start over. # RED-GREEN-REFACTOR for Skills ## RED: Write Failing Test (Baseline) Run pressure scenario with subagent WITHOUT the skill. Document exact behavior: - What choices did they make? - What rationalizations did they use (verbatim)? - Which pressures triggered violations? ## GREEN: Write Minimal Skill Write skill that addresses those specific rationalizations. Run same scenarios WITH skill. Agent should now comply. ## REFACTOR: Close Loopholes Agent found new rationalization? Add explicit counter. Re-test until bulletproof. # SKILL.md Structure **Frontmatter (YAML):** - Only two fields: `name` and `description` - Max 1024 characters total - `name`: Letters, numbers, hyphens only - `description`: Third-person, "Use when..." format - **CRITICAL:** Describe ONLY triggering conditions - **NEVER summarize the skill's process or workflow** - Keep under 500 characters **Why no workflow in description:** Testing revealed that when descriptions summarize workflow, Claude may follow the description instead of reading the full skill content. Descriptions should only answer "Should I read this skill right now?" **Body sections:** ```markdown # Skill Name Core principle in 1-2 sentences. # When to Use Bullet list with SYMPTOMS and use cases When NOT to use # The Process / Pattern Clear, numbered steps or comparison # Red Flags What indicates you're about to violate # Common Rationalizations Table of excuses vs. reality ``` # Key Principles **Token Efficiency:** - Target <200 words for frequently-loaded skills - Move details to tool help - Use cross-references (don't repeat) - Compress examples - Eliminate redundancy **Claude Search Optimization (CSO):** - Keywords: Error messages, symptoms, synonyms, tools - Descriptive naming: Verb-first, active voice - No workflow summaries in description **Bulletproofing Against Rationalization:** - Close every loophole explicitly - Address "Spirit vs Letter" arguments - Build rationalization table from testing - Create red flags list # Testing Skill Types **Discipline-Enforcing Skills (TDD, verification):** - Test with pressure scenarios - Multiple combined pressures (time + sunk cost + exhaustion) - Identify rationalizations, add explicit counters **Technique Skills (how-to guides):** - Application scenarios - Variation scenarios - Missing information tests **Pattern Skills (mental models):** - Recognition scenarios - Application scenarios - Counter-examples # Skill Creation Checklist **RED Phase:** - [ ] Create pressure scenarios (3+ combined pressures) - [ ] Run WITHOUT skill - document baseline verbatim - [ ] Identify patterns in rationalizations **GREEN Phase:** - [ ] Name uses only letters, numbers, hyphens - [ ] Description starts with "Use when..." (no workflow) - [ ] Keywords throughout for search - [ ] Address specific baseline failures - [ ] Run scenarios WITH skill - verify compliance **REFACTOR Phase:** - [ ] Identify NEW rationalizations - [ ] Add explicit counters - [ ] Build rationalization table - [ ] Create red flags list - [ ] Re-test until bulletproof **Deployment:** - [ ] Commit skill to git # The Bottom Line **Creating skills IS TDD for process documentation.** Same Iron Law: No skill without failing test first. Same cycle: RED (baseline) → GREEN (write skill) → REFACTOR (close loopholes). If you follow TDD for code, follow it for skills. --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/mtthsnc) — claim your Tome and manage your conversions.