It hasn’t failed to be useful to me yet, even if it isn’t complete info about what went wrong. Better if you can ask it a specific question about what it did (why do you do X?). Sometimes it made a mistake and you can ask it how you can word instructions better to not make the mistake (useful in prompt engineering), sometimes I made an actual mistake and gave it conflicting instructions, sometimes it’s still something that can be fixed. Eventually it stops making mistakes because you’ve tested it enough and made your prompts robust. I guess your mileage will vary, but my experience is that it’s a conversation to get a good prompt, not a single one shot ask (which is why I save my prompts and reuse them).