Last I checked it still doesn't. A skill that tells your client to call a CLI, and uses the help menus for progressive disclosure, benchmarks better. Developers noticed this immediately and there is sort of an anti-MCP sentiment. The protocol was probably largely conceived for non-coding agents run by non-coders.

In theory the agents could just natively know how to do this better, to get exactly the composability you want. In fact, you could probably just write a CLI mcp-caller and tell the agent to only call MCPs via that, and boom you're done.

Where MCP does come back into the picture even for coders is a more controlled way to break a sandbox.

What I will also say is it matters less and less. It's the usual bitter lesson. The models are just getting so much better all attempts to optimize everything are a drop in the bucket.