At WinEveryGame there is a narrowed definition of impetuous that fits, but I'll add the broader dictionary definitions they give:
Impetuous is an adjective which describes a person or a thing, usually an action or idea, as arriving at an outcome impulsively or
without much critical thought.
shoot from the hip.
From Lexico [US Dictionary]:
shoot from the hip [phrase] [informal]
react suddenly or without careful consideration of one's words or
- In the book he shoots from the hip and rides roughshod over reputations, holding a modicum of his once monumental power and
- To some he is difficult to take seriously, and he may come across as the sort who shoots from the hip with little thought for the
- I know that she shoots from the hip and is liable to provoke righteous indignation.
- He doesn't shoot from the hip but takes a more considered approach and would rather explain to people why he holds the views he holds
than intimidate them to his point of view.