Skill Creator

NutriProfile Skill Creator

You are a skill creation expert. This skill helps you create new Claude Agent Skills following the Anthropic specification.

What Are Skills?

Skills are folders of instructions, scripts, and resources that Claude loads dynamically to improve performance on specialized tasks. They extend Claude's capabilities for specific domains.

Skill Structure

.claude/skills/
└── my-skill-name/
    ├── SKILL.md          # Required: Main skill definition
    ├── references/       # Optional: Additional documentation
    │   ├── api-docs.md
    │   └── examples.md
    ├── scripts/          # Optional: Executable scripts
    │   └── helper.py
    └── assets/           # Optional: Templates, configs
        └── template.json

SKILL.md Format

Required Structure

---
name: skill-name
description: Clear description of what the skill does and when to use it. This is what Claude reads to decide if the skill is relevant.
allowed-tools: Read,Write,Edit,Grep,Glob,Bash
---

# Skill Title

Brief introduction explaining the skill's purpose.

## Context

Background information Claude needs to understand the domain.

## Architecture / Structure

Relevant file structures, components, or systems.

## Key Concepts

Important patterns, rules, or guidelines.

## Examples

Practical examples of how to use the skill.

## Best Practices

Do's and don'ts for the domain.

## Common Tasks

Step-by-step guides for typical operations.

Frontmatter Fields

Creating a New Skill

Step 1: Identify the Need

Ask yourself:

• What specific task or domain does this skill address?
• What context does Claude need that it doesn't have?
• What tools will Claude need to use?

Step 2: Create the Structure

mkdir -p .claude/skills/my-skill-name

Step 3: Write SKILL.md

Start with the template:

---
name: my-skill-name
description: [What it does] for NutriProfile. Use this skill when [trigger conditions]. [Key capabilities].
allowed-tools: Read,Write,Edit,Grep,Glob
---

# NutriProfile [Skill Name] Skill

You are a [domain] expert for the NutriProfile application. This skill helps you [main purpose].

## Context

[Background information about the domain]
- Key files: [relevant paths]
- Technologies: [stack info]
- Relationships: [how it connects to other systems]

## Architecture

[File structure or component diagram]

path/to/files/ ├── file1.ts ├── file2.ts └── ...

## Key Concepts

### [Concept 1]
[Explanation with code examples]

### [Concept 2]
[Explanation with code examples]

## Common Tasks

### Task 1: [Name]
1. Step one
2. Step two
3. Step three

### Task 2: [Name]
[Steps...]

## Best Practices

1. **Do this** - Explanation
2. **Don't do this** - Explanation
3. ...

## Examples

### Example 1: [Scenario]
```typescript
// Code example

Example 2: [Scenario]

[Example...]

### Step 4: Add References (Optional)

For complex skills, split content into reference files:

```markdown
# In SKILL.md
For detailed API documentation, see `{baseDir}/references/api-docs.md`

Step 5: Add Scripts (Optional)

# scripts/helper.py
#!/usr/bin/env python3
"""Helper script for the skill."""

def main():
    # Script logic
    pass

if __name__ == "__main__":
    main()

Reference in SKILL.md:

Run the helper script: `python {baseDir}/scripts/helper.py`

Best Practices for Skills

Description Field

• Be specific: "Manage i18n for 7 languages" not "Handle translations"
• Include triggers: "Use when adding translations..."
• List capabilities: "Covers FR, EN, DE, ES, PT, ZH, AR"

Content Organization

• Keep SKILL.md under 5,000 words
• Use clear headers for parseability
• Include code examples for technical skills
• Reference files instead of embedding everything

Tool Permissions

• Minimal permissions: Only include needed tools
• Document why: Explain tool usage in the skill

Portability

• Use {baseDir} for relative paths
• No hardcoded paths: /home/user/project/ won't work
• No environment assumptions: Don't assume specific OS

NutriProfile Skill Categories

Domain Skills (Application Features)

• nutrition-analyzer - Food detection and nutrition
• recipe-generator - AI recipe generation
• ai-coach - Coaching and gamification

Development Skills (Code Quality)

• test-writer - Testing with Vitest/pytest
• i18n-manager - 7-language translations
• responsive-design - Mobile-first UI

Infrastructure Skills (DevOps)

• api-designer - FastAPI endpoints
• database-manager - PostgreSQL/Alembic
• deployment-manager - Fly.io/Cloudflare

Meta Skills

• skill-creator - This skill!

Skill Discovery

Skills are discovered from:

1. .claude/skills/ - Project-specific skills
2. ~/.config/claude/skills/ - User-wide skills
3. Plugin-provided skills
4. Built-in Anthropic skills

Testing Skills

After creating a skill:

1. Check syntax: Ensure YAML frontmatter is valid
2. Test discovery: Ask Claude about the skill
3. Test activation: Give Claude a task matching the description
4. Verify behavior: Check Claude uses the skill correctly

Example: Creating a Security Skill

---
name: security-auditor
description: Audit NutriProfile code for security vulnerabilities. Use when reviewing authentication, data validation, API security, or RGPD compliance. Covers OWASP Top 10.
allowed-tools: Read,Grep,Glob
---

# NutriProfile Security Auditor Skill

You are a security expert for NutriProfile...

## OWASP Top 10 Checklist

### 1. Injection
- SQL Injection: Use parameterized queries
- Command Injection: Validate all inputs
...

## Authentication Review
...

## RGPD Compliance
...

Troubleshooting

Skill Not Activating

• Check description field clarity
• Ensure name is unique
• Verify YAML syntax

Tools Not Available

• Check allowed-tools field
• Verify tool names are exact

Content Too Long

• Split into reference files
• Remove redundant examples
• Use bullet points over prose