incisive

keen, poignant, trenchant

acerb, acerbic, acid, acidic, acidulous, acrid, barbed, biting, caustic, corrosive, cutting, mordant, pungent, sarcastic, sardonic, satiric (or satirical), scalding, scathing, sharp, smart-aleck, smart-alecky, smart-mouthed, snarky, tart

brisk, cross, sharp-tongued, sour, sourish, spiky (also spikey), tartish

cynical, dry, ironic (also ironical), wry

facetious, flippant, tongue-in-cheek

acrimonious, bitter, resentful, vitriolic

harsh, rough, severe, stringent

abrupt, blunt, brusque (also brusk), concise, crisp, curt, gruff, pithy, snippety, snippy, succinct, terse

backhanded, insincere