🗓️ 19092026 2037

CUSTOM MCP SERVERS

Build an MCP server when an AI application needs a safe, reusable connection to a system that existing servers do not cover.

Good reasons to build one​

  • An internal API, database, or document system needs controlled access.
  • Existing integrations expose too much access or the wrong workflow.
  • Several AI applications need the same capability.

Start with the smallest capability​

Design a server around a few clear tasks. For example, a documentation server might offer a search tool and a read tool. Each tool description should say what it does, what inputs it expects, and important limits.

Keep permissions in the server and underlying system, not in the model prompt. A read-only query tool is safer and easier to reason about than a generic database shell.

Before building​

First check whether an existing server meets the need. Then decide whether the system should be exposed as a tool (perform work), resource (provide context), or prompt (offer a user-selected template). See the MCP overview.

References​