We can't really do much with the information that x amount is reserved for MCP, tool calling or the system prompt.
I actually think this is pretty useful information. It helps you evaluate whether an MCP server is worth the context cost. Similar for getting a feel for how much context certain tool uses use up. I feel like there's a way you can change the system prompt, and so that helps you evaluate if what you've got there is worth it also.
What we need is a way to manage the dynamic part of the context without just starting from zero each time.