It's not enough to say "good pass." You have to tell them why it is a good pass so they can repeat the action. "Great job of passing away from the defense."
Here is a Jim Harbaugh talking about that in an article written by Mitch Albom of the Detroit Free Press:
“You can scream at somebody and tell ’em they did something wrong. Or you can pat ’em on the back, tell ’em they did something right. But you’re still not giving them the tools.
“The teacher or coach that can actually give you the tip or the advice to develop you as a player — those are the real special ones.”