Staying calm and maintaining composure, outwaiting an opponent, generally being cool: these exemplify things your character does with the Cool skill. Cool is something of a defensive skill in nature, since it most often comes up as the skill your character uses to resist attempts to sway or affect them. Cool also represents how your character appears to other people. If your character doesn't want to show that something affected them, they would use the Cool skill to keep their emotions invisible.

Even though Cool isn't a social skill, it is often used in social encounters. If you want to make a character who is particularly effective in social encounters, you may want to invest in Cool.