Select an artefact > press upgrade > press an 'i' icon in the top left. It will open a page with set descriptions.

Yes but the question is a skill like that considered a "cast" or a "lifesteal effect"? It sounds like the latter, but it's best if I ask to clarify since wording can be hard to decipher sometimes, even it sounds simple enough. I remember dealing with semantics back when M:tg was in its early years, and I'm sure it still goes on cause its just that type of game. That and also my brain usually  doesn't always comprehend things right. 

 skills like "attack enemy, heals champion by X%"? 

Nope, it doesn't work. That set works exactly like the crit rate, healings can be criticals.