cool is complicated (and means different things to different generations) : cachet (friendliness, caring, attractiveness, personal competence, drive for success)  vs contrarian (rebellion, irony, toughness, hedonism, thrill-seeking) in journal of individual differences

“If you perceive a peer as rebellious, ironic, rough, etc., then you perceive him or her as cool (by the old-time definition); and if you perceive him or her as cool (a positively valenced word), then you (by the halo effect) perceive him or her as friendly, competent, generous, etc. Thus, the halo effect might win out over the semantic tension between cachet and contrarian traits when judging the coolness of actual people.”