Skills vs MCP

A common question when working with Claude is: when should I use Skills, and when should I use MCP (Model Context Protocol)? This guide clarifies the difference.

TL;DR

• Skills = Knowledge and workflows (what to do)
• MCP = Tools and data access (how to do it)

They're complementary, not competing. Use both together for the best results.

What is MCP?

Model Context Protocol (MCP) is an open standard that lets Claude connect to external tools and data sources. Think of it as giving Claude "hands" to interact with the world.

MCP servers provide:

• Tools: Actions Claude can take (run code, call APIs, query databases)
• Resources: Data Claude can read (files, documentation, live data)
• Prompts: Pre-defined conversation starters

Example MCP servers:

• File system access
• GitHub integration
• Database queries
• Slack messaging
• Browser automation

What are Skills?

Skills are instruction packages that teach Claude specialized workflows and domain knowledge. Think of them as giving Claude "expertise" about how to approach problems.

Skills provide:

• Process knowledge: Step-by-step workflows
• Domain expertise: Best practices and standards
• Context: When and how to apply techniques
• Examples: Reference implementations

Example Skills:

• TDD workflow
• Code review checklist
• API design standards
• Documentation templates

The Key Difference

Aspect	MCP	Skills
Purpose	Access to tools and data	Knowledge and workflows
Analogy	Hands	Brain/expertise
What it provides	Capabilities	Instructions
Example	"Can read/write files"	"How to organize files"

A Practical Example

Task: "Help me review this pull request"

With MCP only:

• Claude can access GitHub API
• Claude can read the diff
• Claude can post comments
• But... Claude doesn't know what to look for

With Skills only:

• Claude knows the code review checklist
• Claude knows what security issues to check
• Claude knows the team's coding standards
• But... Claude can't actually access the PR

With both:

• Claude accesses the PR via MCP (GitHub server)
• Claude applies the code review skill (checklist, standards)
• Claude posts structured feedback via MCP
• Result: Thorough, consistent code reviews

When to Use Each

Use MCP When You Need:

• External data access: Files, APIs, databases
• Action execution: Running commands, posting messages
• Real-time information: Live data, current state
• Integration: Connecting to external services

Examples:
- Reading files from disk
- Querying a database
- Posting to Slack
- Running tests
- Accessing GitHub

Use Skills When You Need:

• Consistent workflows: Same process every time
• Domain expertise: Specialized knowledge
• Best practices: Standards and guidelines
• Structured output: Specific formats

Examples:
- Code review process
- API design standards
- Testing methodology
- Documentation format
- Error handling patterns

Use Both When:

The task requires both access (MCP) and expertise (Skills).

Task	MCP Provides	Skill Provides
Code review	GitHub access	Review checklist
Bug fixing	File access, test runner	Debugging methodology
API development	Database, HTTP tools	Design standards
Documentation	File system	Doc templates, style guide

How They Work Together

Example: Automated Testing Workflow

MCP Server: Test runner, file system access

Skill: TDD Workflow

When implementing features:
1. Write failing test first
2. Implement minimum code to pass
3. Refactor only after tests pass
4. Run full test suite before committing

Result: Claude can run tests (MCP) while following TDD practices (Skill).

Example: Database Migration

MCP Server: Database connection, migration tools

Skill: Migration Best Practices

When creating migrations:
1. Always make migrations reversible
2. Test rollback before deploying
3. Never modify existing migrations
4. Use transactions for data changes

Result: Claude can execute migrations (MCP) while following safety practices (Skill).

Common Misconceptions

"MCP replaces Skills"

No. MCP gives Claude capabilities; Skills tell Claude how to use them effectively.

"Skills are just prompts"

Skills are more structured than ad-hoc prompts. They include:

• Metadata for automatic triggering
• Progressive loading (only loaded when relevant)
• Reference files for extended documentation
• Reusability across projects and conversations

"I only need one or the other"

For simple tasks, maybe. For complex workflows, you'll want both:

• MCP for the "plumbing" (access, execution)
• Skills for the "expertise" (process, knowledge)

Setup Comparison

MCP Setup

// claude_desktop_config.json
{
  "mcpServers": {
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": {
        "GITHUB_TOKEN": "your-token"
      }
    }
  }
}

Skills Setup

~/.claude/skills/code-review/
└── SKILL.md

---
name: code-review
description: Reviews code for bugs, security issues, and style violations.
---

# Code Review Process
...

Summary

Question	Answer
Need to access external data?	Use MCP
Need to execute actions?	Use MCP
Need consistent workflows?	Use Skills
Need domain expertise?	Use Skills
Need both?	Use both!

The best Claude setups combine MCP servers for capabilities with Skills for expertise. They're designed to work together.

Next Steps

• Learn more about What are Claude Skills?
• Get started with Installing Skills
• Explore MCP documentation