incisive

Short definition from Wiktionary

Adjective

1. 1
   Intelligently analytical and concise. (of a person or mental process)
2. 2
   Intelligently analytical and concise. (of a person or mental process): Accurate and sharply focused. (of an account)
3. 3
   Quickly proceeding to judgment and forceful in expression. (of an action)
4. 4
   Having the quality of incising, cutting, or penetrating, as with a sharp instrument; trenchant.
5. 5
   Of or relating to the incisors.