I tagged a few questions with it, just to get the ball rolling and see if we agree on the way it should be used.
I quickly put together the following tag excerpt:
Applies to questions of primarily educational value - styled in the format similar to that found in textbook exercises. This tag should be applied to questions that are (1) stated in the form of an exercise and (2) at the level of basic undergraduate and postgraduate textbooks.
I don't particularly like it, but I guess it's a start. Feel free to improve it, and let me know if you agree with its stated intent. Similarly, let me know if you have alternative proposals for the name (for example I personally wouldn't mind creating some synonym with a shorter name, if only to make it quicker to add).