Skill Creator

Create effective skills that extend Claude's capabilities with specialized knowledge, workflows, and tools.

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.

What Skills Provide

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

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 loaded into context as needed
    └── assets/           - Files used in output (templates, icons, fonts)

Bundled Resources

Scripts (`scripts/`)

Executable code for tasks requiring deterministic reliability or repeated execution.

When to include: Same code rewritten repeatedly, or deterministic reliability needed
Example: scripts/rotate_pdf.py for PDF rotation tasks
Benefits: Token efficient, deterministic, may execute without loading into context

References (`references/`)

Documentation and reference material loaded as needed into context.

When to include: Documentation Claude should reference while working
Examples: Database schemas, API docs, domain knowledge, company policies
Best practice: If >10k words, include grep search patterns in SKILL.md
Avoid duplication: Information lives in SKILL.md OR references, not both

Assets (`assets/`)

Files used within output Claude produces (not loaded into context).

When to include: Files needed in final output
Examples: Templates, images, icons, boilerplate code, fonts
Benefits: Separates output resources from documentation

Progressive Disclosure Design

Skills use a three-level loading system to manage context efficiently:

Metadata (name + description) - Always in context (~100 words)
SKILL.md body - When skill triggers (<5k words)
Bundled resources - As needed by Claude (Unlimited*)

*Unlimited because scripts can execute without reading into context.

Skill Creation Process

Follow these steps in order, skipping only if clearly not applicable.

Step 1: Understand the Skill with Concrete Examples

Goal: Clearly understand how the skill will be used.

Ask questions like:

"What functionality should this skill support?"
"Can you give examples of how this skill would be used?"
"What would a user say that should trigger this skill?"

Conclude when: You have a clear sense of the functionality the skill should support.

Step 2: Plan the Reusable Skill Contents

Goal: Identify what scripts, references, and assets would be helpful.

For each example use case:

Consider how to execute it from scratch
Identify what would be helpful when executing repeatedly

Example analysis:

Skill	Use Case	Reusable Resource
pdf-editor	"Rotate this PDF"	`scripts/rotate_pdf.py`
frontend-builder	"Build me a todo app"	`assets/hello-world/` template
big-query	"How many users logged in?"	`references/schema.md` documentation

Conclude with: A list of reusable resources to include (scripts, references, assets).

Step 3: Initialize the Skill

Run the initialization script to create the skill structure:

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

The script creates:

Skill directory at specified path
SKILL.md template with proper frontmatter and TODO placeholders
Example resource directories: scripts/, references/, assets/
Example files that can be customized or deleted

Skip this step if: Updating an existing skill (proceed to Step 4).

Step 4: Edit the Skill

Remember: The skill is for another Claude instance to use. Include information that would be beneficial and non-obvious.

Start with Reusable Contents

Create the identified scripts, references, and assets
Delete example files/directories not needed
Request user input if needed (e.g., brand assets, documentation)

Update SKILL.md

Writing Style: Use imperative/infinitive form (verb-first instructions), not second person.

✅ "To accomplish X, do Y"
❌ "You should do X"

Answer these questions:

What is the purpose of the skill? (few sentences)
When should the skill be used?
How should Claude use the skill? (reference all bundled resources)

Metadata Quality: The name and description in YAML frontmatter determine when Claude uses the skill. Be specific about what the skill does and when to use it. Use third-person:

✅ "This skill should be used when..."
❌ "Use this skill when..."

Step 5: Package the Skill

Package into a distributable zip file:

scripts/package_skill.py <path/to/skill-folder>

Optional output directory:

scripts/package_skill.py <path/to/skill-folder> ./dist

The script will:

Validate - Check YAML frontmatter, naming conventions, structure
Package - Create zip file with proper directory structure

If validation fails, fix errors and run again.

Step 6: Iterate

After testing the skill:

Use the skill on real tasks
Notice struggles or inefficiencies
Identify how SKILL.md or resources should be updated
Implement changes and test again

SKILL.md Template

---
name: skill-name
description: Brief description of what this skill does and when to use it. Use third-person (e.g., "This skill should be used when..."). Be specific about triggers and use cases.
---

# Skill Name

[One paragraph explaining the skill's purpose and core philosophy]

## Purpose

[What this skill accomplishes]

## When to Use This Skill

- [Trigger 1]
- [Trigger 2]
- [Trigger 3]

**Not for:** [What this skill should NOT be used for]

---

## Workflow

### Step 1: [First Step]
[Instructions]

### Step 2: [Second Step]
[Instructions]

[Continue as needed]

---

## Bundled Resources

- `scripts/[name].py` - [What it does]
- `references/[name].md` - [What it contains]
- `assets/[name]/` - [What it includes]

---

## Related Skills

- **skill-name** - [How it relates]

---

*[Brief closing note or key reminder]*

Best Practices

SKILL.md Guidelines

Keep it focused: One clear purpose per skill
Be specific about triggers: When should this skill activate?
Use imperative voice: "To do X, do Y" not "You should do X"
Reference all resources: Explain how to use bundled scripts/references/assets
Include examples: Show expected inputs and outputs
Add quality checks: Checklists for validating output

Frontmatter Best Practices

name: Lowercase, hyphenated (e.g., anti-ai-writing)
description: 1-3 sentences, third-person, specific triggers
- ✅ "This skill transforms raw transcripts into polished documents. Use when processing podcast or interview recordings."
- ❌ "A transcript processing skill"

Resource Organization

scripts/: Executable code only, no documentation
references/: Documentation only, loaded as needed
assets/: Output resources only, never loaded into context

Context Management

Keep SKILL.md under 5k words
Move detailed reference material to references/
Include grep patterns for large reference files
Avoid duplication between SKILL.md and references

Common Patterns

Workflow Skills

## Workflow

### Phase 1: [Name]
**Goal:** [What this phase accomplishes]

#### Step 1: [Action]
[Instructions]

#### Step 2: [Action]
[Instructions]

### Phase 2: [Name]
[Continue...]

Reference Skills (Knowledge Base)

## Key Concepts

### [Concept 1]
[Explanation]

### [Concept 2]
[Explanation]

## When to Apply

[Guidance on when to use this knowledge]

Tool Integration Skills

## Setup

[Prerequisites and installation]

## Usage

### [Command/Function 1]
```bash
[Example command]

[Explanation]

[Command/Function 2]

[Continue...]


---

## Bundled Scripts

This skill includes helper scripts:

- `scripts/init_skill.py` - Initialize new skill with template structure
- `scripts/package_skill.py` - Validate and package skill for distribution
- `scripts/quick_validate.py` - Quick validation check

### Usage

```bash
# Initialize new skill
./scripts/init_skill.py my-new-skill --path ./skills/

# Package for distribution
./scripts/package_skill.py ./skills/my-new-skill

# Quick validation
./scripts/quick_validate.py ./skills/my-new-skill

Related Skills

voice-analyzer - Create voice style skills
anti-ai-writing - Example of a well-structured skill

Skills are modular, self-contained, and focused. One clear purpose, specific triggers, and all resources referenced in SKILL.md.

skill-creator