Claude Code Skills - Meta Reference

This skill provides the definitive reference for creating, organizing, and maintaining Claude Code skills. Use this when building new skills or improving existing skill architecture.

Quick Reference

Component Purpose Required

SKILL.md

Main reference file with frontmatter Yes

scripts/

Executable code (runs, not loaded) Optional

references/

Documentation (loaded on-demand) Recommended

assets/

Output files (templates, icons) Optional

data/sources.json

Curated external links Recommended

Cross-Platform: Agent Skills standard adopted by Claude Code, Codex CLI, Gemini CLI, and VS Code Copilot. Skills are portable across platforms.

Skill Structure

skills/ └── skill-name/ ├── SKILL.md # Main reference (required) ├── scripts/ # Executable code (Python/Bash) - runs, not loaded │ └── validate.py ├── references/ # Documentation loaded into context on-demand │ ├── patterns.md │ └── examples.md ├── assets/ # Files for OUTPUT (templates, icons, fonts) │ └── template.html └── data/ └── sources.json # External references

Directory purposes:

• scripts/

• Executable code; output consumed, code never loads into context

• references/

• Documentation loaded into context when the agent needs it

• assets/

• Files used in generated output (not loaded into context)

SKILL.md Template

name: skill-name description: One-line description of what this skill provides and when to use it

Skill Name - Quick Reference

Brief overview of the skill's purpose and value.

Quick Reference

When to Use This Skill

The assistant should invoke this skill when a user requests:

• Use case 1
• Use case 2
• Use case 3

Core Concepts

Concept 1

Explanation with code example:

```language code example ```

Concept 2

Additional patterns...

Navigation

Resources

• references/skill-patterns.md - Common patterns
• references/skill-validation.md - Validation criteria

Related Skills

• ../claude-code-agents/SKILL.md - Agent creation

Progressive Disclosure

Skills use progressive disclosure to optimize token usage:

Layer Content Token Cost

Discovery Name + description only ~50 tokens

Activation Full SKILL.md body 2K-5K tokens

Execution scripts/, references/, assets/ On-demand

Pattern: SKILL.md provides overview -> Resources load only when needed

Limits: Keep SKILL.md under 500 lines (<5K tokens)

When to Split Content

Keep in SKILL.md Move to references/

Decision trees Full API references

Quick commands Step-by-step tutorials

Common patterns Edge case handling

1-2 code examples Complete implementations

Frontmatter Specification

name: string # Required: lowercase-kebab-case, matches folder name description: string # Required: PRIMARY trigger mechanism (50-300 chars) disable-model-invocation: boolean # Optional: Only user can invoke (for /deploy, /commit) user-invocable: boolean # Optional: false = background knowledge only

Name rules:

• Use kebab-case: ai-llm , not AI_LLM_Engineering

• Match folder name exactly

• Be specific: software-backend not backend

Description rules (PRIMARY TRIGGER):

• Description is the primary triggering mechanism - the runtime uses it to decide when to invoke

• Include "when to use" context HERE, not in the body

• Single line, 50-300 characters

• Include key technologies/concepts as trigger keywords

Optional frontmatter:

• disable-model-invocation: true

• Only user can invoke (for workflows with side effects: /commit , /deploy , /send-slack )

• user-invocable: false

• Not user-invocable (background knowledge only; runtime-dependent)

Skill Categories

Category Prefix Examples

AI/ML ai-

ai-llm , ai-ml-data-science

Software software-

software-backend , software-frontend

Operations ops-

ops-devops-platform

Data data-

data-lake-platform , data-sql-optimization

Quality qa-

qa-debugging , qa-docs-coverage

Developer Tools dev- , git-

dev-api-design , git-commit-message , dev-workflow-planning

Product product-

product-management , docs-ai-prd

Document document-

document-pdf , document-xlsx

Testing testing- , qa-testing-

qa-testing-playwright , qa-testing-strategy

Marketing marketing-

marketing-social-media , marketing-seo-complete

Claude Code claude-code-

claude-code-agents , claude-code-skills

sources.json Schema

{ "metadata": { "title": "Skill Name - Sources", "description": "Brief description", "last_updated": "YYYY-MM-DD", "skill": "skill-name" }, "category_name": [ { "name": "Resource Name", "url": "https://example.com/docs", "description": "What this covers", "add_as_web_search": true } ] }

Categories should group logically:

• official_documentation

• tutorials

• community_resources

• tools_and_libraries

Quality Checklist

SKILL VALIDATION CHECKLIST

Frontmatter: [ ] name matches folder name (kebab-case) [ ] description is concise and actionable

Structure: [ ] SKILL.md under 500 lines (split into references/ if needed) [ ] references/ for detailed content [ ] data/sources.json with curated links

Content: [ ] Quick reference table at top [ ] "When to Use" section present [ ] Code examples are copy-paste ready [ ] Related skills linked at bottom

Quality: [ ] >40% operational content (code, tables, checklists) [ ] <50% prose paragraphs [ ] All URLs are live (no 404s) [ ] Sources updated within 6 months

Multi-Tech vs Single-Tech Skills

Single-Tech Skill

software-backend/ ├── SKILL.md # Node.js focus └── references/ └── nodejs-patterns.md

Multi-Tech Skill

software-backend/ ├── SKILL.md # Overview + decision tree ├── references/ │ ├── nodejs-patterns.md │ ├── go-patterns.md │ ├── rust-patterns.md │ └── python-patterns.md └── assets/ ├── nodejs/ ├── go/ ├── rust/ └── python/

Navigation

Resources

• references/skill-patterns.md - Common skill patterns

• references/skill-validation.md - Validation criteria

• data/sources.json - Official documentation links

Related Skills

• ../claude-code-agents/SKILL.md - Agent creation

• ../claude-code-commands/SKILL.md - Command creation

• ../claude-code-hooks/SKILL.md - Hook automation