Hmm. The consensus seems to be that short answers are not good. However many of the questions seem to be phrased in ways that encourage brevity. I see many questions that ought to have yes/no answers for example.
Sometimes there is just no long answer. The one asked todayThe one asked today, for example, on why the Buddha answered questions if asked three times. I've never come across any discussion of this in primary or secondary texts (either religious or scholarly). No one knows why. There are very many question to which the answer is "no one knows". Many cultural idioms are like linguistic idioms: there's no reason, it's just what they did. Padding out "no one knows" with speculations for the sake of a longer answer seems unproductive.