When you consider the "tool" as more than just the LLM model, but the stuff wrapped around calling that model then I feel like you can make a good argument it's improving when it keeps context in a file on disk and constantly updates and edits that file as you work throguh the project.

I do this routinely for large initiatives I'm kicking off through Claude Code - it writes a long detailed plan into a file and as we work through the project I have it constantly updating and rewriting that document to add information we have jointly discovered from each bit of the work. That means every time I come back and fire it back up, it's got more information than when it started, which looks a lot more improvement from my perspective.