MCP vs Agent Skills: connections vs know-how

The short answer

An Agent Skill is a folder of instructions, scripts and files (a SKILL.md) that teaches an agent how to do a task, loaded only when relevant. An MCP server gives the agent access to an outside system. A skill might say how your team writes release notes; an MCP server lets the agent read the merged pull requests to write them from.

MCP and Skills side by side

	MCP	Skills
What it adds	Access to outside systems and data	Instructions, procedures and helper scripts
Format	A running server speaking the protocol	A folder with a SKILL.md file
Context cost	Tool descriptions load on connect	A short summary until the skill is used
Needs a network or service	Usually	No, it is files
Can run code	Server-side, whatever the tools do	Scripts in the folder, in the agent's own environment
Best for	Reading from and acting in other apps	Repeatable tasks done your way

What MCP is, in one paragraph

The Model Context Protocol is an open standard, first published by Anthropic in November 2024, for connecting AI applications to outside tools and data. An MCP server describes what it can do (tools the model can call, resources it can read, prompt templates) in a machine-readable way, and any MCP client, such as Claude, Cursor, VS Code or ChatGPT, can connect to it without custom glue code. Messages are JSON-RPC 2.0, sent over standard input and output for a local server or over HTTP for a remote one.

What Agent Skills are

Anthropic introduced Agent Skills in October 2025 and later published the format as an open standard. A skill is a folder with a SKILL.md file: a name, a one-line description of when to use it, and instructions, plus any scripts, templates or reference files the task needs. The agent sees only the short description until a task matches, then loads the rest. That progressive loading is why dozens of skills cost little context.

The difference

MCP answers "what can the agent reach?". A Postgres server lets it query your database; a Linear server lets it read and create issues.

A skill answers "how should the agent do this?". A skill might say: to build our weekly report, query these three tables, compute these metrics, and lay out the document like this template.

A skill with no MCP server can only work with what is already in front of the agent. An MCP server with no skill gives the agent access but leaves it to guess your way of doing things.

Using both

The strongest setups pair them: MCP servers for access, skills for the procedures that use that access. Because skills load only when needed, they can also carry the long, detailed guidance that would be too expensive to put in every MCP tool description.

What to check

Both are code and instructions from someone else. For a skill, read the SKILL.md and scripts before installing, as you would a shell script. For an MCP server, check its safety report: install scripts, what its tools can write, auth on remote endpoints, and hidden instructions in tool descriptions.

Questions people ask

Do Skills replace MCP?

No. Skills carry instructions and scripts; MCP connects to outside systems. A skill often tells the agent how to use tools that an MCP server provides.

Why do Skills use less context than MCP servers?

Only a skill's short description is loaded until a task needs it. An MCP server's tool descriptions are sent when the client connects, whether they are used or not.

Can I use Skills outside Claude?

The SKILL.md format was published as an open standard, and other agents have adopted it, but support varies by client.