Tools · interactive

MCP: tools the model can call

MCP is a socket between your app and a tool server. The server lists what it can do. The model picks one. Your app forwards the call. The model never opens the tool itself.

Model

picks a tool

Your app

MCP client

MCP server

2 tools

get_weather

the real work

Run the call and follow it from the model to the tool and back.

Step 1 of 6 · read left to right

1
Connect to the server
The app opens the MCP server at startup and keeps that connection.
server: local tools
2
Read the tool list
Each tool has a name and a one-line description. That list is what the model is allowed to choose from.
- get_weatherCurrent temperature for a city
- search_docsFind a page in the docs
the question
3
A question arrives
The question decides which tool is useful. Change it and the call changes.
How warm is it in Lahore?
4
The model picks a tool
It names the tool and the arguments. That is a request, not a result.
get_weather({ "city": "Lahore" })
5
The app forwards it
Your app sends the call to the MCP server and waits. The model is idle here.
App → MCP server → get_weather
6
Hand the result back
The server's reply goes back into the conversation. The model's next sentence can use it.
34°C, dry (sample reading)

In production

Tools and technologies

MCP is the wire format between an app and a tool server — any language can implement either side.

Not tied to one language — use these names when you search docs or design a system.