Indeed: why, for example, does a damage spell deal exactly N points of damage, and not a random number in the range from 1 to N?! In my opinion, a tent should heal exactly as much HP as the level of the first aid skill allows - otherwise, what's the point of such a skill?!
And, by the way, it's not entirely useless: for example, only a tent allows you to heal dragons (if you don't have the Sphere of Vulnerability, of course)!
(Василь Симоненко. Люди – прекрасні)