This comparison is part of our MCP comparisons, within The MCP Guide. Facts are checked against each vendor's own documentation and pricing pages on the date shown.
Use MCP when the AI needs to reach a live system, such as a database, CRM or ticketing tool. Use Claude Skills when the AI already has the tools it needs but keeps doing a task the wrong way. Most teams end up with both, because Anthropic positions Skills as a complement to MCP servers, not a replacement.
Checked against: Anthropic's Agent Skills overview, the Skills over MCP extension overview and the 2026-07-28 MCP changelog, read on 28 October 2026.
This is a concept comparison. MCP is an open protocol. Agent Skills are a file format that Anthropic created and later published as an open standard. "Claude Skills" is the common name for Agent Skills used in Claude's products.
Key Takeaways
- An MCP server gives an AI app tools, resources and prompts over a network or local connection.
- A Skill is a folder with a
SKILL.mdfile plus optional scripts and reference files that teach the AI a workflow. - Anthropic says Skills load in stages: about 100 tokens of metadata per Skill at startup, the full instructions only when triggered.
- The Skills over MCP extension lets an MCP server publish Skills; its proposal is Final, but host support is still early.
- Both carry real risk: Anthropic warns a malicious Skill can make Claude "call tools or run code" against its stated purpose.
At a glance
| MCP server | Claude Skill (Agent Skill) | |
|---|---|---|
| What it adds | Actions and live data from outside systems | Written workflows, scripts and reference files |
| Format | JSON-RPC protocol, latest spec 2026-07-28 | A folder with SKILL.md and YAML frontmatter |
| Where it runs | A server process, local or remote | Inside the agent's code execution environment |
| How the AI finds it | Tool list from the server | name and description in the system prompt |
| Context cost | Tool definitions loaded by the client | About 100 tokens per Skill until triggered |
| Works across vendors | Yes, any MCP client | Open standard; support varies by product |
| Needs code execution | No | Yes in claude.ai and the Claude API |
| Own sign-in layer | OAuth for remote servers | None; uses the agent's access |
Where MCP is stronger
Live data and actions. A Skill on the Claude API runs "in a sandboxed container with no network access," Anthropic's overview says. It cannot query your CRM or create a ticket by itself. An MCP server can, because it runs where your systems live. Read what an MCP server is for the basics.
Authentication and access control. Remote MCP servers use the OAuth-based authorization spec, so each user signs in and gets scoped tokens. Skills have no auth layer of their own. They act with whatever access the agent already has.
One integration for many clients. MCP is supported by Claude, ChatGPT, Cursor, VS Code and many other apps. Agent Skills are an open standard too, but each product loads them differently. Anthropic's docs note that custom Skills "do not sync across surfaces," so a Skill uploaded to claude.ai must be uploaded again to the API.
Server-side updates. Change your MCP server and every connected client sees the new tools. Skills live as files in each environment, so you redistribute them.
Where Claude Skills are stronger
Teaching a process. Anthropic describes Skills as packaging "workflows, context, and best practices that turn a general-purpose agent into a specialist." A brand style guide, a month-end checklist or a code review routine fits better in a Skill than in a tool description.
Low context cost. Anthropic's overview lists three levels. Metadata costs about 100 tokens per Skill and is always loaded. Instructions load only when triggered and stay "Under 5k tokens." Bundled files cost nothing until read, and scripts return only their output. You can install many Skills without crowding the context window.
Deterministic scripts. A Skill can bundle a Python script that Claude runs with bash. Anthropic says "the script's code never loads into the context window," only its output. That is cheaper and more reliable than asking the model to write the code each time.
Simple to write. The Agent Skills specification requires only name and description in the frontmatter. Optional fields include license, compatibility, metadata and an experimental allowed-tools list. In Claude Code you drop the folder into ~/.claude/skills/ or .claude/skills/.
Skills over MCP: where the two meet
The 2026-07-28 spec made extensions an official, opt-in part of MCP. One of them is Skills over MCP (io.modelcontextprotocol/skills). The extension overview says servers that declare it "MUST implement skills/list and skills/get," and serve files through resources/read. Serving Skills this way "keeps those instructions with the service they describe."
The Skills Over MCP Working Group page says SEP-2640 is Final, merged on 13 September 2026. The overview adds that "SDK and host support is still being implemented." On 28 October 2026, the source of the extension support matrix marked only the mcpc CLI as supporting Skills. ChatGPT, fast-agent and MCP Inspector were marked Partial. No Claude client was marked. Our Skills over MCP guide covers the protocol.
Anthropic saw this coming. Its October 2025 engineering post on Agent Skills said it would "explore how Skills can complement Model Context Protocol (MCP) servers." A December 2025 update on that page says Anthropic "published Agent Skills as an open standard."
Pricing
MCP: the protocol, spec and official SDKs are free and open source. You pay for hosting your own servers or for the SaaS products behind them.
Skills in Claude apps: Claude's pricing page lists Skills on Free, Pro and Max. Anthropic's Skills overview says uploading custom Skills is "Available on Pro, Max, Team, and Enterprise plans with code execution enabled." Pro is $20 per month billed monthly, or $17 per month billed annually.
Skills on the Claude API: Skills need the code execution tool. Anthropic's code execution docs say each organization gets "1,550 free hours" per month, then "$0.05 USD per hour, per container," with a 5-minute minimum. Code execution is free when the request also includes web search or web fetch. Token costs apply as usual.
Security and admin controls
Treat both like installing software. Anthropic's overview says to use Skills "only from trusted sources: those you created yourself or obtained from Anthropic." It warns that a malicious Skill "can direct Claude to call tools or run code in ways that don't match the Skill's stated purpose." The same caution applies to third-party MCP servers. See MCP tool poisoning.
Network access differs by surface. On the Claude API, Skills have no network access and cannot install packages. In Claude Code, Skills have "the same network access as any other program on the user's computer." In claude.ai, it depends on user and admin settings.
Admin visibility. Anthropic's docs say custom Skills in claude.ai "are not shared organization-wide and cannot be centrally managed by admins." On the API, custom Skills are shared across the workspace.
Integrity checks in Skills over MCP. The extension requires hosts to verify each file's byte size and SHA-256 digest. A changed, added or removed file "revokes that approval." The overview warns digests prove consistency, "not trust in its content."
Which to choose
Pick MCP if:
- The AI must read or change data in another system.
- You need per-user sign-in and scoped permissions.
- You want the same integration in Claude, ChatGPT, Cursor and other clients.
Pick Claude Skills if:
- The AI has the tools but needs your process, format or checklist.
- You want repeatable scripts that run the same way every time.
- You work mainly in Claude Code or the Claude API.
Pick both if your workflow uses external tools in a set order. Put the actions in an MCP server and the method in a Skill. OpenAI's plugin format takes the same view, bundling skills with an MCP server. See MCP vs ChatGPT Apps SDK.
Next step
eSEOspace writes Skills and MCP servers for teams that use Claude Code. See our Claude Code development service, or browse more MCP comparisons. For the bigger picture, read MCP Apps, Tasks and Skills explained.
Frequently asked questions
Do Claude Skills replace MCP?
No. A Skill teaches Claude how to do a task, while an MCP server gives it the tools and data to act. Anthropic describes Skills as a way to complement MCP servers with more complex workflows.
Can an MCP server send Skills to Claude?
The Skills over MCP extension defines how, using skills/list, skills/get and resources/read. On 28 October 2026, the official support matrix did not mark any Claude client as supporting it. Check the matrix before you rely on it.
Are Agent Skills only for Claude?
No. Anthropic published Agent Skills as an open standard, with the spec at agentskills.io. OpenAI's plugins can also include skills. Each product decides how it loads and runs them.
Do Skills need code execution?
In claude.ai and on the Claude API, yes. Anthropic says custom Skills in claude.ai need code execution turned on, and API Skills run inside the code execution tool's container. Claude Code runs Skills on your own computer.
