They’re not the same thing under a different wire protocol!
An MCP tool call that returns the top N spenders puts the result in the agent’s context window.
A CLI tool call on the other hand… The agent can pipe their results into other completely unrelated CLI tools. It can write a loop that calls multiple tools.
These things are not possible with MCP but are trivial with CLIs.
Anthropic proposed a way to programmatically chain MCPs together a while back, I'm not sure if it's been implemented much yet: https://www.anthropic.com/engineering/code-execution-with-mc...