Ah, excellent point.
Generally, if there's a roll involved, talk about what you're attempting to do. "Time slows down and the camera revolves around Chris as he leaps into the air for a spinning roundhouse, aiming at the woman's head".
I'll narrate the effects once I've seen the roll.
As you get a bit more experienced with the system, though, I don't mind you doing that yourself. Once you've internalised what's a hit and so forth, there's really no reason that you can't give the results as well. Does that make sense?
Excellent question, thanks for raising that.