You would think git history should be the first thing an agent would look at, as they make so many mistakes before they get to the correct answer. They don't.

I haven't measured, but documenting bug fixes and architecture seems to help, along with TDD patterns, including integration tests.

I would probably add it to Claude.md to look for all of the above when tackling a new bug.

>Is searching through the current version of your code and possibly git history not enough?

While you can document everything and use git history, I think that having short entries in a kind of memory to remember past decisions, how issues were solved would be much more token efficient than reading lots of documentation and looking at git history and past code.