I don't know about GP's setup, but you give the AI an MCP that can do the thing without exposing the key to the AI directly. An all powerful agent could setup a fake endpoint and send itself requests and exfiltrate the key that way, so don't let it do that.

Indeed. But if it's a model running on your own hardware it isn't as risky. And the Anthropic models are actually pretty good at kind of writing code that will look at contents of a file without fully looking at the content, so it's insecure but not quite as bad as an open("secrets.txt").read()

I wil encourage you to check https://runeward.io this is specifically the usecase we are building this for