Precision First by L. Kimberly Epting on Inside Higher Ed was an interesting read for me.

Indeed, many of my students have revealed this to me when complaining about points not earned on test questions; they have told me, in no uncertain terms, that they have learned to look at the topic of an essay question and then “just write pretty much everything [they] know about that topic.” This seems reasonable if the test prompt is “tell me everything you know about X,” but I can tell you the exact number of times I have written such an item: zero. Truthfully, I recognize I had a similar history, at least until advanced courses in college -- filling up the space on the page with at least related information generally produced favorable consequences.

Students also often ask if items on my tests are “trick questions.” My standard answer is that I never intend items to be “trick questions”; however, they are intended to be specific, precise questions. It occurs to me this might be an important revelation from them: focusing on specificity in reading and answering a short-answer/essay item is so unfamiliar to them, they find it suspect when required to do so. And they are genuinely confused when they receive no credit for filling up the space on the page with accurate, related information that nonetheless never addresses the actual prompt or question. This alarms me.

Training people to guess the teacher's password has consequences.