First, you can use FSS to see a recruit's potential. This will tell you if the recruit has low, average or high potential for each category. Low translates to 0-5 points of potential, average 6-20 and high 21+.
You can also use scouting trips (or evaluations or whatever they are called) to determine a recruit's potential. Your assistant coach will give you messages on four different categories (randomly). There are message for low minus, low plus, average, high minus, high plus potential (I prefer this terminology because it is unambiguous). Low minus means 0-1 points of improvement, low plus 2-5, average 6-20, high minus 21-30*, high plus 31+. (*Some coaches use 28 instead of 30 here.)
If you go to the Critical Information forum, there is a chart of the messages for each category so you can recognize high minus vs high plus.