How to tell OpenAI when to use your MCP

GPT builders Plugins / Actions builders
1

It looks like ChatGPT does not support MCP’s Server Instructions.

I am currently telling the model WHEN to use my MCP on the tool descriptions.

But it seems like it does not read that until it calls list_resources.

So my question is how to tell it when to use my MCP?

2

ChatGPT actually does support MCP server instructions now! MCP servers can return an instructions field during initialization, and ChatGPT and Codex use these instructions alongside your tool metadata when deciding how to work with your server. You should make sure you keep the instructions concise though and make the first 512 characters of the instructions self-contained since that’s usually what’s surfaced to the model.