Morpheon is right...by rate it means how frequently, and the lower the value the better. It wouldn't really make sense for a skill to get worse as you put more points into it.
Anyways, I used it last time I played the game (I think I had 3 points in it) and there was never a time when I thought "oh man, I'm glad I have that". It's kinda nice to be gaining life while exploring, but if you're in a fight, regenerating a few points of health every 8 time units isn't gonna do much for you...
