> 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.

Sure, it's useful, once.

What we need is a way to manage the dynamic part of the context without just starting from zero each time.

My theory is that you will never get this from a frontier model provider because as is alluded to in sibling thread the context window management is actually a good hunk of the secret sauce that makes these things effective and companies do not want to give that up