Julien Dev Skill Creator

Skill Creator

Enhanced guidance for creating effective skills with proper structure and documentation.

Core Principles

Concise is Key

Context window is shared. Only add what Claude doesn't already know. Challenge each piece: "Does this justify its token cost?"

Progressive Disclosure (3 Levels)

1. Metadata (name + description) - Always in context (~100 words)
2. SKILL.md body - When skill triggers (< 500 lines)
3. Bundled resources - As needed by Claude

Skill Structure

skill-name/
├── SKILL.md (required, < 500 lines)
│   ├── YAML frontmatter (name, description required)
│   └── Markdown instructions
└── Bundled Resources (optional)
    ├── scripts/      - Executable code
    ├── references/   - Documentation loaded on-demand
    └── assets/       - Output resources (templates, images)

Key rules:

• References must be one level deep from SKILL.md
• Files > 100 lines need table of contents at top
• Use forward slashes only (not Windows backslashes)
• No extraneous files (README.md, CHANGELOG.md, etc.)

Naming & Description

See references/naming-conventions.md for full guidelines.

Quick rules:

• Name: max 64 chars, lowercase + hyphens, gerund form preferred (processing-pdfs)
• Description: max 1024 chars, third person, include "what + when to use"

Skill Creation Process

Step 1: Understand with Examples

Ask clarifying questions:

• "What functionality should this skill support?"
• "Give examples of how it would be used"
• "What should trigger this skill?"

Step 2: Plan Reusable Contents

For each example, identify:

• Scripts needed (deterministic/repeated code)
• References needed (schemas, docs, policies)
• Assets needed (templates, images)

Step 3: Initialize Skill

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

Or copy template: cp -r assets/template-skill/ path/to/new-skill/

Step 4: Edit the Skill

YAML Frontmatter

---
name: skill-name
description: What it does. Use when [specific triggers].
---

Body Instructions

Write using imperative form (verb-first). Reference bundled resources clearly.

Document Skill Chaining (Critical)

Add Skill Chaining section at end. See references/skill-chaining-template.md for complete template.

Required subsections:

1. Skills Required Before
2. Input Expected
3. Output Produced
4. Compatible Skills After
5. Called By
6. Tools Used
7. Visual Workflow
8. Usage Example

Step 5: Package Skill

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

Validates then creates .skill file.

Step 6: Add Semantic Routing Triggers

Add triggers to configs/skill-triggers.json for automatic skill suggestion:

{
  "name": "your-skill-name",
  "triggers": [
    "keyword1", "keyword2",
    "full phrase that triggers this skill",
    "phrase en français aussi"
  ],
  "description": "Short description | Description courte"
}

Tips:

• Include both keywords AND full phrases
• Add French and English variants
• Test with python scripts/benchmark-semantic-router.py

Step 7: Iterate with Self-Assessment

Never fix everything at once. Each iteration focuses on ONE improvement.

1. Score against quality rubric (see references/quality-rubric.md)
2. Identify top 3-5 gaps
3. Fix ONE dimension per iteration
4. Re-score until average ≥ 3.5/5

Reference Files

Degrees of Freedom

Match specificity to task fragility:

What NOT to Include

• README.md, INSTALLATION_GUIDE.md, CHANGELOG.md
• User-facing documentation
• Setup/testing procedures
• Any auxiliary context about creation process

Security & Portability

Security Checklist

• ✓ No hardcoded credentials (passwords, API keys, tokens)
• ✓ Sensitive data in .env file
• ✓ .env added to .gitignore
• ✓ Instructions use environment variables ($VAR or source .env)

Portability Checklist

• ✓ Use relative paths (.env, ./scripts/) instead of absolute paths
• ✓ Use ~/.claude/skills/ for user paths, not hardcoded home directories
• ✓ Avoid platform-specific paths (e.g., C:\Users\... in examples)
• ✓ Use forward slashes only (not Windows backslashes)

Anti-Patterns to Avoid

❌ Description >200 chars (breaks progressive disclosure) ❌ Content >300 lines (too much detail) ❌ Duplicates existing docs (should reference instead) ❌ Development notes in content (timestamps, changelog) ❌ Generic/vague description (doesn't explain when to use) ❌ Second-person language ("you should...") ❌ Information in both SKILL.md and references files ❌ Hardcoded credentials (passwords, API keys, database credentials, tokens) ❌ Sensitive data in code examples (use placeholders or .env variables) ❌ Absolute paths in examples (/home/user/..., C:\Users\...) ❌ Platform-specific paths (Windows-only or Unix-only examples)

Skill Chaining

Skills Required Before

• None (entry point skill for skill creation)

Input Expected

• User request to create/improve a skill
• Domain knowledge or examples from user
• Optional: existing skill to improve

Output Produced

• Format: Complete skill directory with SKILL.md + resources
• Side effects: Creates files in specified path
• Duration: 10-30 minutes depending on complexity

Compatible Skills After

Recommandés:

• julien-dev-tools-skill-reviewer: Review and score the created skill

Called By

• Direct user invocation: "Create a skill for X"
• Skill improvement workflows

Tools Used

• Read (usage: read existing skills, templates)
• Write (usage: create SKILL.md, references)
• Bash (usage: run init_skill.py, package_skill.py)
• Edit (usage: modify existing skills)

Visual Workflow

User: "Create skill for X"
    ↓
[THIS SKILL]
    ├─► Step 1: Gather examples
    ├─► Step 2: Plan resources
    ├─► Step 3: Initialize structure
    ├─► Step 4: Write SKILL.md + refs
    ├─► Step 5: Package
    ├─► Step 6: Add semantic triggers
    └─► Step 7: Iterate
    ↓
skill-name.skill created
    ↓
[Optional] skill-reviewer for quality check

Usage Example

Scenario: Create deployment skill for VPS

Command: "Create a skill for deploying to my Hostinger VPS"

Result:

• hostinger-deployment/SKILL.md created
• hostinger-deployment/references/ with server docs
• hostinger-deployment/scripts/ with deploy scripts
• Packaged as hostinger-deployment.skill