Skill Creator

Purpose

Guide for creating effective, token-efficient skills for AI agents. Covers skill structure, progressive disclosure, validation, and packaging.

What Skills Provide

1. Specialized workflows - Domain-specific procedures
2. Tool integrations - File format/API instructions
3. Domain expertise - Company knowledge, schemas, business logic
4. Bundled resources - Scripts, references, assets

Core Principles

Be Concise

Context window is shared. Only add what the agent doesn't already know. Challenge every piece of content: "Is this essential?" Prefer examples over explanations.

Use Persuasion Principles

Skills that enforce discipline or guide decisions should use persuasion principles from the research on LLM compliance (Cialdini 2021, Meincke et al. 2025). These techniques more than doubled compliance rates (33% → 72%).

Key principles for skills:

• Authority: Imperative language "YOU MUST", "Never", "Always", "No exceptions"
• Commitment: Require announcements, explicit choices, tracking (TodoWrite)
• Scarcity: Time-bound requirements "Before proceeding", "Immediately after X"
• Social Proof: Universal patterns "Every time", "Always", "X without Y = failure"
• Unity: Collaborative language "our codebase", "we're colleagues"
• Reciprocity: Use sparingly - can feel manipulative
• Liking: DON'T USE for compliance - conflicts with honest feedback

Skill type combinations:

Ethical test: Would this serve the user's genuine interests if they fully understood it?

See references/persuasion-principles.md for full details and examples.

Set Appropriate Freedom

• High (text instructions): Multiple valid approaches
• Medium (pseudocode/parameterized scripts): Preferred pattern with variation
• Low (specific scripts): Fragile operations requiring consistency

Skill Structure

skill-name/
├── SKILL.md (required)
│   ├── YAML frontmatter (name, description)
│   └── Markdown instructions
└── Bundled Resources (optional)
    ├── scripts/     - Executable code
    ├── references/  - Loaded as needed
    └── assets/      - Used in output

SKILL.md Frontmatter (YAML): name and description determine when skill loads.

Description template:

description: |
  <What it does>. Use when <context>, <context>, or <context>—e.g., "<example>", "<example>".

See references/skill-description-guide.md for full guidance.

Body (Markdown): Loaded AFTER skill triggers. Instructions for execution.

Scripts: Deterministic operations rewritten repeatedly. Token-efficient, tested, self-contained, and executable via shebang (never python <script>), without loading to context.

References: Documentation loaded on-demand. Keeps SKILL.md lean. Examples: schemas, API docs, policies, detailed guides.

Assets: Output files (templates, images, boilerplate). Not loaded to context.

Progressive Disclosure

Three-level loading:

1. Metadata - Always in context (~100 words)
2. SKILL.md body - When triggered (<500 lines)
3. Resources - As needed

Keep SKILL.md under 500 lines. Split content when approaching limit. Link references clearly with guidance on when to read them.

Patterns:

• Domain-specific organization: Separate files per domain/framework
• Checklists: Systematic evaluation references
• Examples: Show desired output format/quality

See references/effective-patterns.md for detailed patterns and anti-patterns.

Creation Workflow

0. skill-creator/scripts/ usage

All the scripts in skills/skill-creator/scripts/ are self-contained full scripts with shebangs. They should be run directly (e.g. ./init_skill.py <args>) and made executable (chmod +x <script>). Never run them via python <script>.

1. Understand with Examples

Gather concrete use cases. Ask:

• What functionality?
• Example requests?
• What should trigger this skill?

2. Plan Resources

For each example, identify reusable content:

• Scripts for repeated code
• References for schemas/docs
• Assets for templates/boilerplate

3. Initialize

skills/skill-creator/scripts/init_skill.py <skill-name> --path <output-directory>

Creates template with SKILL.md, example directories.

4. Edit Skill

Write for another AI agent instance. Include non-obvious procedural knowledge.

If the skill will produce recommendations or influence decisions, include ethical persuasion guidance and a self-review checklist. See references/persuasion-principles.md.

Consult:

• references/effective-patterns.md - Patterns & anti-patterns
• references/workflows.md - Sequential/conditional workflows
• references/output-patterns.md - Output format guidance

Frontmatter:

• name: Skill identifier (kebab-case)
• description: Determines when skill loads. Format: <What it does>. Use when <contexts>—e.g., "<examples>".
  • See references/skill-description-guide.md for template and examples

Body: Use imperative form. Write clear instructions. Link references with guidance.

Test scripts by running them directly (shebang). Delete unused example files.

5. Package

skills/skill-creator/scripts/package_skill.py <path/to/skill-folder> [output-dir]

Validates then packages as .skill file (zip with .skill extension).

Validation checks:

• YAML format and required fields
• Naming conventions
• Description quality
• File organization

See references/validation-checklist.md for complete checklist.

6. Iterate

Test on real tasks. Note inefficiencies. Update skill. Repeat.

Include this requirement in every skill you create.

Key Rules

DO:

• Keep SKILL.md under 500 lines
• Put all "Use when" contexts in description (body loads after triggering)
• Link references with clear usage guidance
• Always use the skill-creator scripts for creation, validation, and packaging
• Run skills/skill-creator/scripts/quick_validate.py on the skill folder after edits
• Test scripts before packaging
• Execute scripts directly via shebang (never python <script>) and ensure they are executable
• Use imperative/infinitive form
• Include a clear "Purpose" section at the top of every skill
• Include ethical persuasion guidance when the skill recommends or persuades
• Avoid manipulation tactics (fear, shame, false urgency, fabricated social proof)

DON'T:

• Create README.md, INSTALLATION.md, or auxiliary docs
• Duplicate content between SKILL.md and references
• Put "Use when" info in body (too late—already triggered)
• Nest references deeply (keep one level from SKILL.md)
• Include setup/testing procedures (for AI only)

References (Load on Demand)

• references/effective-patterns.md - Load for patterns, anti-patterns, and skill design guidance
• references/workflows.md - Load when designing sequential or conditional workflows
• references/output-patterns.md - Load for output format guidance and contracts
• references/persuasion-principles.md - Load when writing recommendation, persuasion, or decision-support guidance
• references/skill-description-guide.md - Load for description template and examples
• references/validation-checklist.md - Load before packaging to verify all requirements