Wants can be vague but practical. Like this: They want a sour apple; they want blood of brothers to be spilled; they want something usefull but not too flashy. And, likewise, a want can be abstract but way too specific: they want peace, they want sharpness, and so onn. In my opionin, the more pratical anything is, the less work a dm has to do in order to get what's going on and the more efforet they can put on run the actual adventure. It's just my opinion and my preference, but i felt it could be usefull for me to explain myself a little more