Skill Creator

Skill Creator

This skill provides guidance for creating effective skills.

About Skills

Skills are modular, self-contained packages that extend Claude's capabilities by providing specialized knowledge, workflows, and tools. Think of them as "onboarding guides" for specific domains or tasks—they transform Claude from a general-purpose agent into a specialized agent equipped with procedural knowledge that no model can fully possess.

What Skills Provide

1. Specialized workflows - Multi-step procedures for specific domains
2. Tool integrations - Instructions for working with specific file formats or APIs
3. Domain expertise - Company-specific knowledge, schemas, business logic
4. Bundled resources - Scripts, references, and assets for complex and repetitive tasks

Core Principles

Concise is Key

The context window is a public good. Skills share the context window with everything else Claude needs: system prompt, conversation history, other Skills' metadata, and the actual user request.

Default assumption: Claude is already very smart. Only add context Claude doesn't already have. Challenge each piece of information: "Does Claude really need this explanation?" and "Does this paragraph justify its token cost?"

Prefer concise examples over verbose explanations.

Set Appropriate Degrees of Freedom

Match the level of specificity to the task's fragility and variability:

• High freedom (text-based instructions): Use when multiple approaches are valid.
• Medium freedom (pseudocode or scripts with parameters): Use when a preferred pattern exists.
• Low freedom (specific scripts, few parameters): Use when operations are fragile, consistency is critical, or a specific sequence must be followed.

Anatomy of a Skill

Every skill consists of a required SKILL.md file and optional bundled resources:

skill-name/
├── SKILL.md (required)
│   ├── YAML frontmatter (name + description required)
│   └── Markdown instructions
└── Bundled Resources (optional)
    ├── scripts/       - Executable code
    ├── references/    - Documentation loaded as needed
    └── assets/        - Files used in output (templates, icons, etc.)

SKILL.md Frontmatter

• name (required): The skill name
• description (required): What the skill does and when to trigger it. Be comprehensive—this is the primary triggering mechanism.

SKILL.md Body

Instructions and guidance, loaded after the skill triggers. Keep under 500 lines; split into reference files when approaching this limit.

Progressive Disclosure

Skills use three loading levels:

1. Metadata - Always in context (~100 words)
2. SKILL.md body - When skill triggers (<5k words)
3. Bundled resources - As needed (unlimited)

Skill Creation Process

1. Understand the skill with concrete examples from the user
2. Plan reusable contents (scripts, references, assets)
3. Create the SKILL.md with proper frontmatter and instructions
4. Test by using the skill on real tasks
5. Iterate based on actual usage

Writing the SKILL.md

• Use imperative/infinitive form
• description field should include all "when to use" triggers (body is loaded after triggering)
• Only add context Claude doesn't already have
• Prefer concise examples over verbose explanations
• Keep essential workflow in SKILL.md; move detailed reference material to separate files

What NOT to Include

Do not create extraneous files: README.md, INSTALLATION_GUIDE.md, CHANGELOG.md, etc. The skill should only contain what an AI agent needs to do the job.