Tanks
Hold aggro? Marking enemies? Know the mechanics well, or listen to someone who did? Stop and wait for people or just run thru? (This includes waiting for players to catch up or recover MP/TP.) Did you ask if we were capable of pulling the entire room, or just do it and hope for the best?

Healer
Anyone die? Remove debuffs? Know when to use certain spells? Pull to much hate? Did you help DPS or did you just stand in the background doing nothing but casting Cure every 10 seconds or so...?

DPS
Know fight mechanics, what to attack and when? Attack the targets in the order the tank marked them? Did you work with the team or do your own thing? Did you pull mobs instead of waiting for the tank to do it? Ranged DPS stand so close that they got hit with debuffs or had to run away to dodge? Did the right person LB at the right time, or even use LB at all? Know your rotations and deal good damage?