I have found, that the best way to prevent bad output with AI is proper planning, and also extensive end to end tests. - If it is implementing a design, I have it compare the screenshot with the mockup and get 97% similarity. - If it is a functionality, I have it spin up a browser/tv/mobile and check the output is what i asked for.

I also use plannotator for planning, that is an amazing tool! need to buy them some coffees for sure.