Ask about dog aggression. You want to look for parents who won't back down when challenged and will stand their ground, but will not go looking for fights. There's a big difference here. Ask about energy level. While all Kerries are active, some border on the hyper-active.
Some people thoroughly appreciate a very active dog, and others are driven crazy by it.
Try to determine where you stand on the issue. Ask about the level of obedience training. A dam or sire that has earned an obedience title may imply a willingness to please-a trait that could be imparted to the litter. And ask how the parents interact with strangers. Some Kerries are wary of strangers and protective of their owners.