At cbk.ai we dynamically load MCPs into the context when the LLM needs them and unload them when finished. The cost for doing this is negligible and it scales well.

The good think about MCP is the authentication story. It is almost perfect. Compare this with CLIs which mostly piggy back on quirky browser authentication, env files and other bad practices. It is a security nightmare. It is certifiably insane.

So to compare MCPs to CLIs purely on token cost is missing the entire point that at the end of the day these agents need to operate safely and OAuth is the defacto standard where this can be done in somewhat consistent way across different vendors.