Skill Builder

Skill Builder

Use when creating or refactoring local skills. Optimize for clear triggering, progressive disclosure, minimal duplication.

Boundary

Covers:

• creating new local skill under skills/
• restructuring large skill into references/
• tightening metadata, taxonomy, trigger descriptions
• removing redundancy between SKILL.md and detailed references

Principles

• prefer extending existing skill or ref over creating new skill
• keep SKILL.md lean and procedural
• move detailed examples, variants, deep reference material into references/
• write descriptions around trigger conditions, not vague topics
• avoid duplicating repo-wide rules already covered elsewhere
• one skill = one clear domain or workflow

Workflow

1. Choose the smallest natural home

Prefer this order:

1. existing ref inside existing skill
2. existing skill with clearer SKILL.md
3. new skill only when gap is real and recurring

2. Write strong metadata

Frontmatter should make triggering obvious:

• what skill is for
• when it should be used
• what requests activate it

3. Keep SKILL.md to the essentials

Put in SKILL.md:

• purpose
• boundary
• workflow
• selection guidance for refs
• guardrails

Move to references/:

• long examples
• variant-specific guidance
• framework-specific details
• large checklists or catalogs

4. Avoid duplication

Do not repeat same content across:

• SKILL.md and references/
• sibling skills
• commands or agents unless their mandate truly differs

5. Validate the skill

Check:

• name is short and understandable
• description is specific enough to trigger correctly
• refs linked clearly from SKILL.md
• skill matches current repo taxonomy

Run:

uv run rumdl check skills/*/SKILL.md skills/*/references/*.md

Guardrails

• do not create README or changelog files inside skill
• do not make SKILL.md dumping ground for all related knowledge
• do not create nested reference chains when one level is enough
• do not split skill into refs unless split improves selection and context use