Does dumping your entire repository into an AI actually backfire?

I used to think that giving an AI assistant access to every single file in my project folder was the ultimate cheat code. But lately I’ve noticed the exact opposite happening.

When it sees old legacy code from three years ago alongside my clean new components, it gets confused and starts copying the bad habits of the codebase. Sometimes a smaller tightly controlled prompt works way better than letting it scan everything.

Have you started restricting your coding assistant's file access, or do you still feed it the whole repo?