Skill Creator

This skill provides guidance for creating effective skills.

About Skills

Skills are modular, self-contained packages that extend the agent's capabilities by providing specialized knowledge, workflows, and tools. Think of them as "onboarding guides" for specific domains or tasks - they transform the agent from a general-purpose assistant into a specialized agent equipped with procedural knowledge.

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: system prompt, conversation history, other Skills' metadata, and the actual user request.

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

Prefer concise examples over verbose explanations.

Anatomy of a Skill

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

skill-name/
├── SKILL.md (required)
│   ├── YAML frontmatter metadata (required)
│   │   ├── name: (required)
│   │   └── description: (required)
│   └── Markdown instructions (required)
└── Bundled Resources (optional)
    ├── scripts/          - Executable code (Python/Bash/etc.)
    ├── references/       - Documentation intended to be loaded into context as needed
    └── assets/           - Files used in output (templates, icons, fonts, etc.)

SKILL.md (required)

Every SKILL.md consists of:

• Frontmatter (YAML): Contains name and description fields. These are the only fields that determine when the skill gets used, thus it is very important to be clear and comprehensive in describing what the skill is, and when it should be used.
• Body (Markdown): Instructions and guidance for using the skill. Only loaded AFTER the skill triggers (if at all).

Bundled Resources (optional)

Scripts (scripts/)

Executable code (Python/Bash/etc.) for tasks that require deterministic reliability or are repeatedly rewritten.

• When to include: When the same code is being rewritten repeatedly or deterministic reliability is needed
• Example: scripts/rotate_pdf.py for PDF rotation tasks
• Benefits: Token efficient, deterministic, may be executed without loading into context

References (references/)

Documentation and reference material intended to be loaded as needed into context.

• When to include: For documentation that the agent should reference while working
• Examples: references/schema.md for database schemas, references/api_docs.md for API specifications
• Benefits: Keeps SKILL.md lean, loaded only when needed

Assets (assets/)

Files not intended to be loaded into context, but rather used within the output.

• When to include: When the skill needs files that will be used in the final output
• Examples: assets/logo.png for brand assets, assets/template.html for HTML templates
• Benefits: Separates output resources from documentation

Skill Creation Process

Skill creation involves these steps:

1. Understand the skill with concrete examples
2. Plan reusable skill contents (scripts, references, assets)
3. Create the skill directory structure
4. Write SKILL.md with proper frontmatter
5. Add bundled resources as needed
6. Test and iterate based on real usage

Skill Naming

• Use lowercase letters, digits, and hyphens only
• Prefer short, verb-led phrases that describe the action
• Name the skill folder exactly after the skill name

Writing Guidelines

Always use imperative/infinitive form.

Frontmatter

Write the YAML frontmatter with name and description:

• name: The skill name (required)
• description: This is the primary triggering mechanism for your skill. Include both what the Skill does and specific triggers/contexts for when to use it. Include all "when to use" information here - Not in the body.

Body

Write instructions for using the skill and its bundled resources. Keep SKILL.md body to the essentials and under 500 lines to minimize context bloat.

Skill Storage Locations

Skills can be stored in multiple locations with the following priority (higher priority overrides lower):