I find it somewhat excessive (and I still make poor cards even my by own guidelines all the time), but I try optimize to make my flashcards as easy as possible to answer according to [1].
Especially in the long run once you get thousands of flashcards, and have a few breaks because of life. A general rule of thumb I go by is that my answer should be shorter than the question.
Even in your answer there's three or four separate parts to it. You have:
1. An abstract data type 2. collection of elements 3. Two principal operations 3a. Pop and push