A short description wouldn't hurt for the sake of completeness, but it is up to you how brief or verbose you wish to be.
The way this list is set up, you can avoid reading ahead when you get to an area you have not been to yet, either with the different sections, or for each description, giving the region and general area first, then the specific location.
If you design your guide in a similar manner, you wouldn't necessarily need to use spoiler tags, though that would certainly be one way to provide an general info for those who just want to check that they have completed an area before continuing, as well as detailed directions for those who are trying to find a specific book or don't mind getting spoilers.
If you are going to use spoiler tags, though, I'm not sure why the post battle tower stuff would be more important to hide than earlier skill and stat points.
