Skill architect

<essential_principles>

How Skills Work

1. Skills Are Prompts

A skill is not documentation — it is a prompt injection. Everything added competes for the context window. Only include context Claude doesn't already have.

2. SKILL.md Is Always Loaded

When a skill activates, Claude reads SKILL.md — guaranteed. Essential principles belong here (inline). Workflow-specific content belongs in workflows/. Reusable knowledge belongs in references/. This is progressive disclosure.

3. Description Drives Discovery

The description field is the only thing Claude reads at discovery time. A great skill that never triggers is useless. Third person. What + when. Specific trigger phrases. Slightly pushy — Claude under-triggers more than over-triggers.

4. Both Format Styles Are Valid

The old create-agent-skills skill mandated "pure XML, no markdown headings." This is wrong. The agentskills spec has no format restrictions. Anthropic uses markdown headings in all their official skills. XML works well for complex orchestration. Choose based on complexity, not convention.

5. Explain WHY, Not Just What

Avoid rigid ALWAYS/NEVER rules without reasoning. LLMs generalize from principles better than from rigid rules. If you find yourself writing ALWAYS in all caps, explain why instead.

</essential_principles>

<intake> What would you like to do?

1. Choose architecture — decide between simple, router, or domain-expertise pattern
2. Create a new skill — gather intent, choose architecture, delegate to skill-creator
3. Create a domain expertise skill — full lifecycle (build/debug/test/optimize/ship)
4. Audit an existing skill — check against spec, generate report, offer fixes
5. Add a component — add a workflow, reference, template, or script to an existing skill
6. Upgrade to router — convert a simple skill to router pattern
7. Optimize description — improve triggering accuracy via skill-creator's eval loop
8. Get guidance — help with a specific question about skill design or best practices

Wait for response before proceeding. </intake>

<routing>

Response	Workflow
1, "architecture", "which pattern", "what kind"	workflows/choose-architecture.md
2, "create", "new", "build", "make"	workflows/create-skill.md
3, "domain", "expertise", "lifecycle", "full lifecycle"	workflows/create-domain-expertise.md
4, "audit", "check", "review", "analyze"	workflows/audit-skill.md
5, "add", "component", "workflow", "reference", "template", "script"	workflows/add-component.md
6, "upgrade", "router", "convert", "refactor"	workflows/upgrade-to-router.md
7, "optimize", "description", "triggering", "discovery", "CSO"	workflows/optimize-description.md
8, "guidance", "help", "question", "advice"	Answer from references — read references/writing-philosophy.md and references/architecture-patterns.md

Intent-based routing (if the user provides clear intent without selecting a menu item):

• "create a skill for X", "build a new skill", "I need a skill that..." → workflows/create-skill.md
• "audit this skill", "what's wrong with my skill", "check my SKILL.md" → workflows/audit-skill.md
• "what architecture should I use", "simple or router?", "should I use XML?" → workflows/choose-architecture.md
• "add a workflow to my skill", "add a reference", "add a script" → workflows/add-component.md
• "my skill never triggers", "skill isn't being used", "fix description" → workflows/optimize-description.md
• "upgrade this skill", "convert to router" → workflows/upgrade-to-router.md
• "create a domain expertise skill", "full lifecycle skill", "comprehensive domain skill" → workflows/create-domain-expertise.md

After reading the workflow, follow it exactly. </routing>

<skill_creator_integration>

skill-creator is the Primary Creation Tool

Anthropic's skill-creator skill handles all creation, eval loops, and description optimization. skill-architect handles architecture decisions and auditing; skill-creator handles building and testing. Never substitute skill-architect's own templates for skill-creator unless skill-creator is genuinely unavailable.

Prerequisite check

skill-creator must be installed as a project skill. Check before any creation or optimization workflow:

ls .claude/skills/skill-creator/SKILL.md 2>/dev/null || echo "NOT FOUND"

If not found, stop and tell the user: "skill-creator must be installed in .claude/skills/skill-creator/ before I can proceed with skill creation or description optimization. Auditing, upgrading, and adding components work without it."

Once confirmed available

Read .claude/skills/skill-creator/SKILL.md and proceed under its guidance.

</skill_creator_integration>

<quick_reference>

Spec Cheat Sheet

---
name: skill-name              # lowercase+hyphens, max 64 chars, matches directory
description: ...              # max 1024 chars, third person, what+when+triggers
license: Apache-2.0           # optional
compatibility: Requires git   # optional, max 500 chars
allowed-tools: Bash(git:*) Read  # optional, experimental — scope narrowly
metadata:                     # optional, string-to-string map
  author: my-org
---

Validate: skills-ref validate path/to/skill

Three patterns:

• Simple — one intent, single SKILL.md, under 200 lines
• Router — multiple intents, workflows/ + references/, intake+routing in SKILL.md
• Domain expertise — full lifecycle, exhaustive references, for both direct use and knowledge loading

</quick_reference>

<reference_index>

Domain Knowledge

All in references/:

Spec: spec-fields.md — all frontmatter fields, constraints, Claude Code extensions Architecture: architecture-patterns.md — three patterns and decision tree Philosophy: writing-philosophy.md — why skills are prompts, format choices, conciseness Scripts: script-design.md — when to bundle scripts, agent-friendly design Failures: anti-patterns.md — common issues and how to fix them

</reference_index>

<workflows_index>

Workflows

All in workflows/:

Workflow	Purpose
choose-architecture.md	Decide between simple, router, domain-expertise
create-skill.md	Create a new skill (delegates to skill-creator)
create-domain-expertise.md	Build a full-lifecycle domain skill
audit-skill.md	Check skill against spec; generate report
add-component.md	Add workflow, reference, template, or script
upgrade-to-router.md	Convert simple skill to router pattern
optimize-description.md	Improve description for triggering accuracy

</workflows_index>