The Complete Guide
to Building Skills
for Claude
The logo for Claude, featuring a white stylized asterisk or starburst icon to the left of the word "Claude" in a dark serif font.
Contents
| Introduction | 3 |
| Fundamentals | 4 |
| Planning and design | 7 |
| Testing and iteration | 14 |
| Distribution and sharing | 18 |
| Patterns and troubleshooting | 21 |
| Resources and references | 28 |
Introduction
A skill is a set of instructions - packaged as a simple folder - that teaches Claude how to handle specific tasks or workflows. Skills are one of the most powerful ways to customize Claude for your specific needs. Instead of re-explaining your preferences, processes, and domain expertise in every conversation, skills let you teach Claude once and benefit every time.
Skills are powerful when you have repeatable workflows: generating frontend designs from specs, conducting research with consistent methodology, creating documents that follow your team's style guide, or orchestrating multi-step processes. They work well with Claude's built-in capabilities like code execution and document creation. For those building MCP integrations, skills add another powerful layer helping turn raw tool access into reliable, optimized workflows.
This guide covers everything you need to know to build effective skills - from planning and structure to testing and distribution. Whether you're building a skill for yourself, your team, or for the community, you'll find practical patterns and real-world examples throughout.
What you'll learn:
- • Technical requirements and best practices for skill structure
- • Patterns for standalone skills and MCP-enhanced workflows
- • Patterns we've seen work well across different use cases
- • How to test, iterate, and distribute your skills
Who this is for:
- • Developers who want Claude to follow specific workflows consistently
- • Power users who want Claude to follow specific workflows
- • Teams looking to standardize how Claude works across their organization
Two Paths Through This Guide
Building standalone skills? Focus on Fundamentals, Planning and Design, and category 1-2. Enhancing an MCP integration? The "Skills + MCP" section and category 3 are for you. Both paths share the same technical requirements, but you choose what's relevant to your use case.
What you'll get out of this guide: By the end, you'll be able to build a functional skill in a single sitting. Expect about 15-30 minutes to build and test your first working skill using the skill-creator.
Let's get started.
Fundamentals
What is a skill?
A skill is a folder containing:
- • SKILL.md (required): Instructions in Markdown with YAML frontmatter
- • scripts/ (optional): Executable code (Python, Bash, etc.)
- • references/ (optional): Documentation loaded as needed
- • assets/ (optional): Templates, fonts, icons used in output
Core design principles
Progressive Disclosure
Skills use a three-level system:
- • First level (YAML frontmatter): Always loaded in Claude's system prompt. Provides just enough information for Claude to know when each skill should be used without loading all of it into context.
- • Second level (SKILL.md body): Loaded when Claude thinks the skill is relevant to the current task. Contains the full instructions and guidance.
- • Third level (Linked files): Additional files bundled within the skill directory that Claude can choose to navigate and discover only as needed.
This progressive disclosure minimizes token usage while maintaining specialized expertise.
Composability
Claude can load multiple skills simultaneously. Your skill should work well alongside others, not assume it's the only capability available.
Portability
Skills work identically across Claude.ai, Claude Code, and API. Create a skill once and it works across all surfaces without modification, provided the environment supports any dependencies the skill requires.
For MCP Builders: Skills + Connectors
💡 Building standalone skills without MCP? Skip to Planning and Design - you can always return here later.
If you already have a working MCP server , you've done the hard part. Skills are the knowledge layer on top - capturing the workflows and best practices you already know, so Claude can apply them consistently.
The kitchen analogy
MCP provides the professional kitchen: access to tools, ingredients, and equipment.
Skills provide the recipes: step-by-step instructions on how to create something valuable.