On all the skills I have seen so far, as the skill level progresses the description changes. Like Crassus has a passive autoblock skill
lvl 1 6 second cooldown
lvl 2 5 second cooldown
and so on, but for his 3rd skill, the description doesn't change on my screen, so I am not sure what leveling the skill actually does. No matter what level the skill, the description is still 30% Max HP increase and the cooldown for the skill remains the same. So don't know if there is something I am missing while reading or if there is a text update needed for this skill progression.