[Feature Request] Display breakdown of token used by each tool or mcp

Currently, `/usage` shows the total usage of tools. However, sometimes, I would like to understand the token usage of each tool / mcp so that I can make a better decision on which tool/mcp I want to keep by default and which ones I want to disable and only enable when I need it to save on the context window.

Alternatively, these information can be displayed in `/tools` or `/mcp`.