Wait what? Cloaks add that passive effect since when? :O Never heard of that before. 🙂
As for description on the items – oh, well – my suggestion would be more or less like this: Do not read anything items say (especially not armor set effects), try items on, check your stats and see what happens = The best way to check what bonuses you get with a specific item equipped. Some descriptions are just completely off – sad but true.
It is not that you do not understand, it is that you do not even question.