· Hugo Berton
What is an MCP server? A plain-English guide for small businesses
MCP, the Model Context Protocol, is an open standard that Anthropic introduced in November 2024. It defines one common way for an AI application to reach outside tools and data: a database, a spreadsheet, your mailbox, a business app. An MCP server is the small program that exposes those tools; an MCP client is the AI application that uses them.
What an MCP server does
A server describes what it offers in a standard format: tools the assistant can call (search the CRM, create a draft invoice), resources it can read (a folder, a table) and ready-made prompts. Any client that speaks MCP can discover those capabilities and use them, without a custom integration written for each AI vendor.
Desktop assistants and code editors were among the first clients. The specification itself is public, with dated versions, at modelcontextprotocol.io.
Why it matters for a small business
Without a standard, connecting an assistant to your own systems means writing one integration per tool and per AI provider. With MCP, you expose a system once, as a server, and keep the freedom to change the model or the assistant later.
In practice, it is how an assistant can answer from your real data (an order status, an unpaid invoice) instead of guessing.
What to watch before you use one
Permissions first: a server can only be as safe as the access it is given. Give it the minimum, read-only where possible, and require a human approval for anything that sends, pays or deletes.
Community servers vary a lot in quality. Read the code or use servers from the vendor of the tool you connect, and pin the version you tested.
Text that comes back from a tool can contain instructions written by someone else. That is the prompt injection risk, and it applies to every assistant that reads outside content.
In short
MCP is the plug between an assistant and your systems. It is useful as soon as you want an assistant to act on your own data, and it should be set up with the same care as any other access to those systems.