My own dumb TUI agent, I gave a built in `lobotomize` tool, which dumps a text list of everything in the context window (short summary text plus token count), and then lets it Eternal Sunshine of the Spotless Agent things out of the window. It works! The models know how to drive that tool. It'll do a series of giant ass log queries, filling up the context window, and then you can watch as it zaps things out of the window to make space for more queries.
This is like 20 lines of code.