Skill Creator

Skill Creator

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

About Skills

Skills are modular packages that 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 tasks

Core Principles

Concise is Key

The context window is a public good. Only add context Claude doesn't already have. Challenge each piece: "Does Claude really need this?" Prefer concise examples over verbose explanations.

Set Appropriate Degrees of Freedom

• High freedom (text instructions): Multiple approaches valid, context-dependent
• Medium freedom (pseudocode/parameterized scripts): Preferred pattern exists, some variation OK
• Low freedom (specific scripts): Fragile operations, consistency critical

Progressive Disclosure

Three-level loading to manage context efficiently:

1. Metadata (name + description) - Always in context (~100 words)
2. SKILL.md body - When skill triggers (<5k words, under 500 lines)
3. Bundled resources - As needed (unlimited, loaded on demand)

Skill Anatomy

skill-name/
├── SKILL.md              # Required: frontmatter + instructions
├── scripts/              # Optional: executable code (Python/Bash)
├── references/           # Optional: docs loaded into context as needed
└── assets/               # Optional: files used in output (templates, icons)

SKILL.md Frontmatter

Only name and description are required. The description is the primary trigger — it determines when the skill loads.

---
name: my-skill
description: Use when [specific triggering conditions and symptoms]
---

Description rules:

• Start with "Use when..." — focus on triggering conditions
• Include specific symptoms, situations, and contexts
• Write in third person
• NEVER summarize the skill's workflow in the description (Claude may follow the summary instead of reading the full skill)

Bundled Resources

• scripts/: Deterministic, reusable code. Token-efficient. Test by running them.
• references/: Documentation Claude reads as needed. Keep SKILL.md lean by moving detailed info here. For large files (>10k words), include grep patterns in SKILL.md.
• assets/: Files for output (templates, images, fonts). Not loaded into context.

Do NOT include: README.md, CHANGELOG.md, INSTALLATION_GUIDE.md, or auxiliary docs about the creation process.

Creation Process

Step 1: Understand with Concrete Examples

Ask the user:

• What should the skill support?
• Example usage scenarios?
• What triggers should activate this skill?

Step 2: Plan Reusable Contents

For each example, identify what scripts, references, and assets would help when executing these workflows repeatedly.

Step 3: Initialize the Skill

Create the skill directory with a SKILL.md containing frontmatter (name + description) and the appropriate resource subdirectories (scripts/, references/, assets/) as needed.

Step 4: Edit the Skill

Consult these guides based on your needs:

• Multi-step processes: See references/workflows.md
• Output formats/quality standards: See references/output-patterns.md
• Official authoring guidance: See references/anthropic-best-practices.md

Start with reusable resources, then write SKILL.md. Use imperative/infinitive form.

Step 5: Validate & Package

Verify the skill has valid frontmatter (name + description, kebab-case name, under 1024 chars), then package with zip -r skill-name.skill skill-name/ if distributing.