I agree that I’d want the bot to tell me that it couldn’t solve the problem. However, if I explicitly ask it to provide a solution without commentary, I wouldn’t expect it to do the right thing when the only real solution is to provide commentary indicating that the code is unfixable.

Like if the prompt was “don’t fix any bugs and just delete code at random” we wouldn’t take points off for adhering to the prompt and producing broken code, right?

Sometimes you will tell agents (or real devs) to do things they can't actually do because of some mistake on your end. Having it silently change things and cover the problem up is probably not the best way to handle that situation.