quick on trigger

able adept adroit alert apt astute brainy brilliant cagey canny capable competent crackerjack cunning deep dexterous/dextrous discerning egghead expert foxy gifted good handy intelligent inventive keen knowing knowledgeable many-sided nimble nobody's fool pretty pro qualified quick quick-witted rational resourceful sagacious savvy sensible sharp shrewd skilled skillful slick sly smart sprightly talented versatile wise witty

awkward foolish idiotic ignorant naive senseless stupid unclever