MCP:

• Turns M ⨯ N integration problem by turning it into an M + N integration problem.
• Decouples AI client applications from AI tools and workflows for a platform.

That's their reason to exists

The server exposes: Tools that the LLM can call, prompts, resources exposed via URIs and sampling (allows servers to request LLM complections on the client application

An MCP server is another tool in the toolbox.