create-skill: Skill Scaffolding Executor

Scaffolds a complete, standards-compliant agent skill directory. Handles filesystem operations, template rendering, name validation, and discovery — then hands off to the TDD quality gate.

Scope: This skill owns structure. It does not own content quality or routing accuracy. Those are governed by os-skill-improvement (see cross-plugin handoff below).

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Inputs

• $ARGUMENTS — optional skill name or brief use-case description passed as initial context to the discovery phase. Omit to start with open discovery.

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Phase 1: Discovery Interview

Before writing any files, capture all required inputs:

1. Skill name — lowercase-hyphen slug (e.g. link-validator). Validate: no spaces, no special characters, no shell injection sequences (reject names containing ;, &, |, $, `).
2. Purpose — one sentence: what does this skill do and when does it fire?
3. Target plugin — which plugin directory will own this skill?
4. Trigger phrases — 3-5 specific phrases a user would say to invoke it.
5. Tools needed — which allowed-tools does it require?

If $ARGUMENTS is provided, treat it as a starting point and confirm rather than re-ask.

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Phase 2: Plan and Confirm

Present the proposed directory layout before writing anything:

plugins/<plugin>/skills/<skill-name>/
  SKILL.md
  evals/
    evals.json
  references/
    acceptance-criteria.md
  ./scripts/         (if the skill needs Python helpers)
  ./assets/          (if the skill needs static resources)

Confirm with the user before proceeding. If a directory with that name already exists:

"Warning: <path> already exists. Overwrite? (yes/no)" Do NOT overwrite without explicit confirmation.

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Phase 3: Scaffold

Create the confirmed directory structure. Standards enforced by acceptance-criteria.md:

• Python only — helper scripts go in scripts/*.py. Never generate .sh bash scripts.
• Starter SKILL.md — frontmatter with name, description (use the purpose from Phase 1; MUST NOT exceed 1024 characters), allowed-tools. Body: stub sections for Identity, Steps, and Common Failures.
• Starter evals.json — at least 2 placeholder eval cases using the should_trigger schema:

  { "id": "eval-1-positive", "type": "positive", "prompt": "REPLACE", "should_trigger": true }
  { "id": "eval-2-negative", "type": "negative", "prompt": "REPLACE", "should_trigger": false }
  

  ⚠️ Schema requirement: Always use should_trigger: true/false. The legacy expected_behavior string field is ignored by the eval scorer and will produce 0% accuracy.

• acceptance-criteria.md — write to references/acceptance-criteria.md with the acceptance criteria captured in Phase 1.

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Phase 4: Quality Gate Handoff

Dependencies

• os-skill-improvement (agent-agentic-os plugin)

[!TIP] See INSTALL.md for instructions on how to install missing dependencies.

If os-skill-improvement is available, hand off immediately after scaffolding:

Invoke os-skill-improvement on the newly scaffolded skill at <path>.
The RED scenario is: [trigger phrase from Phase 1 discovery].
Run the RED-GREEN-REFACTOR cycle to verify routing accuracy before shipping.

If not available, advise the user:

Scaffold complete. To verify routing accuracy and trigger description quality, ensure **os-skill-improvement** is installed. See [INSTALL.md](https://github.com/richfrem/agent-plugins-skills/blob/main/INSTALL.md).

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Phase 5: Report

✅ Scaffolded: plugins/<plugin>/skills/<skill-name>/
   Files created: SKILL.md, evals/evals.json, references/acceptance-criteria.md
   Quality gate: [PASSED via ~~skill-improvement | SKIPPED — ~~eval-gate not installed]
   Next: fill in REPLACE placeholders in evals/evals.json, then run ~~eval-gate baseline

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Edge Cases

• Empty $ARGUMENTS: begin with Phase 1 discovery — do not skip to scaffolding
• Existing directory: dual-confirmation before any overwrite (see Phase 2)
• Improving an existing skill: redirect to ~~skill-improvement capability — that skill owns content quality and routing improvement. create-skill is for net-new scaffolding only.
• Scaffold script crash: read the Python stack trace, correct obvious errors, or surface the full trace to the user — do not silently skip
• Template rendering failure: do not output partially-rendered content; provide the base template inline and instruct the user to fill values manually

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References

• acceptance-criteria.md — structural pass/fail criteria
• fallback-tree.md — error handling procedures
• ~~skill-improvement (~~eval-gate capability — see CONNECTORS.md): TDD methodology, RED scenario protocol, eval gate.
• ~~eval-gate (~~eval-gate capability — see CONNECTORS.md): autoresearch eval loop for skill optimization.