Huge +1 on explicitly setting expectations. I've written on this topic[0], and there are a lot of different ways interviewers don't set expectations:

- Is the interviewer looking for syntactically correct code, or general algorithmic skills?

- For a warmup, is the interviewer looking for a basic solution, or an optimal solution?

- For architecture walkthroughs, what level of detail is expected?

The extra pressure is definitely unnecessary.

[0] https://hiringfor.tech/2020/03/02/are-you-asking-candidates-...