powered by the apocalypse – The Coolness attribute seems a bit broken to me. How to effectively use it as a GM?

It’s worth considering the context of coolness.

From p7 of core.

Coolness measures the player character’s cool. A cool
character is good at stealth, theft, and other situations
demanding quick decisions under stress.

The focus is stealthy acts, and remaining cool under pressure while you solve things with an agile mind. It isn’t on generally succeeding at all situations where you are under pressure.

Before making a roll a coolness one, consider if this is the sort of thing a thief would do in their core role, and do well. If not, it’s not coolness.

So, yes to picking a lock. Classic thief move. Yes to disarming a trap, thieves have to disarm traps in their path, no to perceiving a path, that would be perceptiveness, finding the way isn’t a stealth thing.

This would be my list of common acts which fall under coolness- assassinations, stealing stuff, sneaking around, disarming traps, using lies to persuade people, parkour, and sleight of hand.

You could make a similar list for any stat. Insight say, might include emotionally destroying people, finding out secrets from people, picking the safest path based on the people, healing trauma, navigating a complex social situation to find a person, and cold reading.

Reason would be being right about facts, finding monster weaknesses, finding out secrets from books, investigating a location to find the safest route, identifying where someone is from, detecting forensic information.

Each stat will have things they’re good and bad at.