1. What answers would lead to a hire and what answers would lead to a reject
2. Does this align with someone able/not able to do the job.
Without these the interview question doesn't provide you the information you need as an interviewer.
4. Is this a puzzle question with only one answer, or are there subproblems they can still solve and I will get actionable data from?
When interviewing, you should be looking for evidence that the candidate might be able to deal with the problems that they are confronted with in their new role. Questions should be directed to finding that evidence, and answers can basically provide you with evidence, provide you with evidence to the contrary or be neutral. At the end of the interview you hopefully have collected enough evidence so that you are convinced the candidate is able to successfully work in the problem space their new role brings.