I think OP's point was that the person gives a vague answer off the top of their head instead of checking the doc to see what the actual concrete type is.
If the extra info in the documentation wasn’t actually important to the code implementation, I’d be more annoyed.
If the goal of asking is to help me grow as a dev, please directly tell me what it is I need to learn.
It seems like the OP is just as vague as the junior dev when it comes to communicating.
If the senior dev saw something in the junior dev’s code and thought it was important to look at the documentation, why not just tell the junior dev that? Why does the senior dev have to tiptoe around and ask leading questions?