What Is an MCP Server? The Standard That Lets AI Agents Use Your Tools

Denis Kildishev -

An MCP server is a program that exposes tools, data and actions to AI assistants through the Model Context Protocol, an open standard introduced by Anthropic in late 2024 and now supported by Claude, ChatGPT, Cursor, VS Code and most agent frameworks. The server describes what it can do in a standard format, and any MCP-compatible client can discover those capabilities and call them.

In plain terms: MCP is to AI assistants what USB is to peripherals. Instead of every assistant needing a custom integration with every tool, each tool ships one MCP server and every assistant can use it.

What MCP server means

MCP stands for Model Context Protocol. "Context" is the key word. A language model on its own knows only its training data and the prompt. An MCP server gives it context from outside: the rows in your database, the tickets in your help desk, the files in a drive, and the ability to act on them.

An MCP server typically exposes three kinds of things:

  • Tools: actions the model can call, such as "create_invoice" or "search_orders", each with a described input schema.
  • Resources: data the model can read, such as a document, a table or a file.
  • Prompts: reusable templates for common tasks.

How an MCP server works

There are three roles. The host is the application a person uses, such as Claude Desktop or Cursor. The client lives inside the host and holds a connection to each server. The server wraps a system, such as GitHub, Postgres or Slack, and exposes it.

When you ask the assistant a question, it sees the list of available tools with their descriptions, decides which one to call, sends the call to the server, gets the result back and continues. Servers run locally over standard input and output, or remotely over HTTP with authentication.

MCP server examples

  • GitHub: read issues and pull requests, open a branch, comment on a review.
  • Postgres or Supabase: list tables, run read-only queries, describe a schema.
  • Slack: search channels, post a message.
  • Google Drive: search and read documents.
  • Stripe: look up customers and payments, create refunds.
  • Internal APIs: a company wraps its own order or ticket API so assistants can use it.

MCP server vs API

An API tells a developer which endpoints exist and what they return. An MCP server adds what a model needs to use them: natural-language descriptions of each tool, when to call it and what the inputs mean. Many MCP servers are thin wrappers over an existing API. For the full comparison, see MCP vs API.

What to check before connecting one to business data

MCP makes it easy to give an AI assistant real power, which is exactly why it needs care:

  • Whose credentials does it use? A server running with an admin database key gives every user of the assistant admin access.
  • Read or write? Start read-only. Add write tools one at a time, with approval for anything that moves money or deletes data.
  • Which rows and fields? The server should respect the same row- and column-level rules a person would have.
  • Is it logged? Every tool call should be recorded with the user, the arguments and the result.
  • Where did the server come from? Third-party servers run code on your machine or network. Review them like any dependency.

Where Jet Admin fits

The hard part of putting AI on business data is not the protocol, it is the permissions. Jet Admin connects to 200+ data sources and runs apps and AI agents inside one role model, so an agent sees the same rows, columns and actions as the person using it. Granular permissions, SSO and audit logs are on the Business plan and above; on-premise and air-gapped deployment are on the Enterprise plan.

Frequently asked questions

What does MCP stand for?

Model Context Protocol, an open standard for connecting AI models to external tools and data.

Is an MCP server the same as an AI agent?

No. The agent is the model deciding what to do. The MCP server is a tool provider the agent calls.

Do I need to write code to use an MCP server?

To use an existing one, usually not: you add it to the assistant's configuration. To build one for an internal system, you write a small program with an MCP SDK.

Are MCP servers secure?

They are as secure as the credentials and permissions behind them. Use scoped credentials, start read-only and log every call.

Give AI access without giving away the keys

Start with Jet Admin for free and build agents that run inside your permissions.