Skill Forge

Skill Forge

Create new skills or edit existing ones following the suite's established patterns. Auto-detects mode based on whether the skill directory already exists — no separate create/edit workflow needed.

Why this exists

Every skill in this suite was built by Claude, and every hard-won lesson (always-on descriptions causing loops, subagent DB write failures, stale file references) lives in the validation checklist. Without this skill, each new skill risks repeating those mistakes.

Inputs

• Skill name — user provides or describes what they want
• Skill purpose — what problem it solves, when it triggers
• Existing SKILL.md (edit mode) — the file to modify
• references/skill-template.md — canonical SKILL.md structure
• references/validation-checklist.md — anti-patterns and validation rules

Outputs

• skills//SKILL.md — created or updated
• skills//references/ — only if progressive disclosure is needed
• skills//agents/ — only if the skill dispatches Sonnet subagents
• Validation report (PASS/WARN/FAIL against the checklist)

Instructions

Phase 1: Detect mode

Check whether skills//SKILL.md exists.

• Exists → edit mode. Read the current file. Identify what to change.
• Does not exist → create mode. Gather intent.

If the user hasn't provided a name, ask for one. Naming conventions:

• Review lenses: -review (e.g., performance-review)
• Action skills: verb or verb-noun (e.g., cache-warm, db-migrate)

Phase 2: Gather intent

Ask the user (skip questions they've already answered):

1. What does this skill do? One sentence.
2. What triggers it? User says "X", or part of which lifecycle skill.
3. What does it need? Inputs — files, project docs, external data.
4. What does it produce? DB records, files, side effects.
5. Does it dispatch Sonnet subagents? Determines if agents/ is needed.
6. Is it a review lens? If yes: fresh-findings check, finding format, severity levels, summary, execution mode required.
7. Does it need reference files? Large catalogs, checklists, prompt templates that would push SKILL.md over 280 lines.

For edit mode also ask: What's wrong with the current version?

Present a brief plan before writing:

Mode: create | edit
Name: 
Type: review lens | action | utility
Sections: [list]
References: [list]
Agent prompts: [list]

Wait for user approval before proceeding.

Phase 3: Scaffold (create mode only)

mkdir -p skills/
mkdir -p skills//references   # only if reference files are needed
mkdir -p skills//agents       # only if dispatching Sonnet subagents
mkdir -p skills//templates    # only if generating project files

Phase 4: Write SKILL.md

Read references/skill-template.md for the canonical structure.

Follow the template exactly. Key rules:

Frontmatter:

• name: matches directory name
• description: ≤ 250 characters, third person, trigger-focused, no always-on language
• disable-model-invocation: true on lifecycle skills (user-triggered only)
• argument-hint: only if the skill accepts arguments

Body — section order per template:

1. Title
2. Why this exists (1-3 sentences)
3. Inputs
4. Outputs (Pattern A: DB; Pattern B: files; Pattern C: side-effect)
5. Instructions (numbered phases, imperative form, exit conditions)
6. Execution Mode — only for review lenses
7. References — only if reference files exist
8. Examples (2-4)
9. Cross-cutting footer

Review lens specifics (if this is a review lens):

• Fresh Findings Check as first instruction step (db_age_hours /references/`
• Linked from SKILL.md as Read references/X.md for [purpose]

Agent prompt templates:

• Live in skills//agents/
• Use XML tags and [PLACEHOLDER] markers for runtime values
• Referenced as Read agents/X.md for the prompt template

Phase 6: Validate

Read references/validation-checklist.md and check every applicable rule:

1. Frontmatter (F1-F6)
2. Structure (S1-S9)
3. Content quality (C1-C6)
4. Anti-patterns (A1-A10)
5. Artifact DB integration (D1-D5) — if the skill uses the DB
6. Driver boundary (B1-B5) — if the skill dispatches Sonnet subagents
7. Progressive disclosure (P1-P5) — if reference files exist
8. Infrastructure (I1-I4) — if the skill spawns external workers

Report using the validation summary format from the checklist.

Any FAIL = fix before finishing. Warnings are advisory.

Phase 7: Report

Tell the user:

• Files created/modified (with paths)
• Validation result (PASS / WARN / FAIL)
• Any warnings that weren't fixed and why
• Whether the skill needs wiring into /review (for lenses) or referenced from another lifecycle skill

Examples

User: I need a skill that reviews database query performance.
→ Create mode. Review lens type. Inputs = codebase + schema. Outputs = DB findings.
  Scaffold, write SKILL.md with fresh-findings check, query analysis steps,
  finding format. Validate. Suggest wiring into /review's default-tier.

User: The security-review description is too long, fix it.
→ Edit mode. Read current SKILL.md. Trim description to ≤ 250 chars while
  preserving trigger phrases. Re-validate.

User: /skill-forge dependency-audit
→ Create mode with name provided. Ask remaining questions. Scaffold and build.

User: Add a "What If" scenarios section to the test-review skill.
→ Edit mode. Read test-review/SKILL.md. Add section following existing pattern.
  Check if content should live in references/ instead. Validate.

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Before completing, read and follow ../../references/cross-cutting-rules.md.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: trevorbyrum
• Source: trevorbyrum/claude-skills-suite
• License: MIT

Install and usage instructions live in the source repository linked above.