The skill under test is for that part is “can solve ambiguous problems”, and what you want to see is that the candidate is able to recognize that a problem is ambiguous.

I think the hard part is recognizing that a problem is ambiguous. Telling someone that a problem is ambiguous kind of defeats the point. IMO, it’s not about reading someone’s mind, but recognizing that there are multiple interpretations to what somebody has SAID. That seems less like a mind-reading technique and more like, you know, a communication skill.

I have gotten lots of ambiguous problems during my career, it seems only fair to have them appear during an interview.