common-skill-creator

# Agent Skill Creator Standard

## **Priority: P0 — Apply to ALL skills**

Maximize **Token ROI**. Every line in SKILL.md must provide specific procedural value. **Activation** (how it triggers) and **Implementation** (how it helps) are the primary quality metrics.

## Three-Level Loading System

- **Level 1** Frontmatter: `name` + `description` (Activation Anchor), ≤100 words.
- **Level 2** SKILL.md body: Core Rules + Workflows (Implementation Core), ≤100 lines.
- **Level 3** references/: Detailed examples, schemas, and "TESTS.md" (On-demand).

## Workflow (New or Existing Skill)

**New skill:**

1. **Research** — web-search domain best practices, checklists, and standards; extract key terms → triggers, workflows → guidelines, mistakes → anti-patterns. See [Web Search Research](references/web-search-research.md).
2. **Capture intent** — what does it do, when does it trigger, expected output format?
3. **Write SKILL.md** — draft using [TEMPLATE.md](references/TEMPLATE.md)
4. **Test** — spawn parallel subagents: one with-skill, one without-skill (baseline)
5. **Evaluate** — grade assertions, review benchmark (pass rate, tokens, time)
6. **Iterate** — rewrite based on feedback, rerun into next iteration dir, repeat
7. **Optimize description** — run trigger eval queries, target ≥80% accuracy

**Existing skill:**

1. **Audit** — run Quality Checklist below; identify violations
2. **Snapshot** — `cp -r <skill-dir> <workspace>/skill-snapshot/` before any edits
3. **Improve SKILL.md** — fix violations, compress, move oversized content to `references/`
4. **Test** — spawn parallel subagents: one with-new-skill, one with-snapshot (baseline)
5. **Evaluate & iterate** — same as steps 4–5 above
6. **Optimize description** — re-run trigger eval if description changed

See [Eval Workflow](references/eval-workflow.md) for full testing + iteration details.

## Description Quality (Activation)

- **Third-Person Voice**: Use `Standardizes...`, `Audits...`, `Encrypts...`. Avoid "I will" or "This skill helps to".
- **What + When Structure**:
  - **What**: Define 5–8 specific capabilities (e.g., "Generates JWT tokens, rotates keys").
  - **When**: Explicitly define triggers (e.g., "Use when user says 'rotate keys'").
- **Specificity**: Avoid vague verbs like "manage" or "handle". Use "Validate", "Inject", "Refactor", "Sanitize".
- **Trigger Hint**: Include a `(triggers: *.ext, keyword)` suffix for technical skills.

## Content Quality (Implementation)

- **No Redundant Knowledge**: Do **NOT** explain concepts the AI already knows (e.g., HTTP status codes, standard library docs, basic SOLID principles). Focus strictly on _project-specific_ rules.
- **Actionability**: Examples must be copy-paste ready and executable.
- **Workflow Clarity**: Use sequential ordered lists for multi-step processes.
- **Progressive Disclosure**: Move code blocks >10 lines to `references/`.

## Anti-Patterns

- **No "AI-splaining"**: Do not explain why a pattern is good unless it's a unique project constraint.
- **No Vague Triggers**: Never use `src/**` or `**/*`. Be surgical.
- **No Description Bloat**: If a description exceeds 100 words, some capabilities belong in the body.
- **No long code blocks**: >10 lines → extract to `references/`
- **No redundancy**: don't repeat frontmatter content in body

## Quality Checklist (Tessl-Aligned)

- [ ] **Activation ≥ 90%**: Description covers both capabilities ("What") and triggers ("When").
- [ ] **Implementation ≥ 90%**: No general-purpose explanations; all examples are executable.
- [ ] **Structural Compliance**: SKILL.md ≤ 100 lines; code blocks moved to `references/`.
- [ ] Trigger rate ≥80% on should-trigger queries.

## References

- [Skill Template](references/TEMPLATE.md) — load when starting a new skill from scratch
- [Anti-Patterns Detail](references/anti-patterns.md) — load when fixing or reviewing anti-pattern format
- [Size & Limits](references/size-limits.md) — load when SKILL.md approaches 100 lines
- [Resource Organization](references/resource-organization.md) — load when deciding where to place content (scripts/, references/, assets/)
- [Testing & Trigger Rate](references/testing.md) — load when writing evals or measuring trigger rate
- [Eval Workflow](references/eval-workflow.md) — load when running parallel subagent tests
- [Full Lifecycle](references/lifecycle.md) — load for complete phase-by-phase creation guide
- [Web Search Research](references/web-search-research.md) — load when creating a skill for an unfamiliar or non-engineering domain