Overhasty
/ˌəʊvərˈheɪsti/
Definition 1 of 1
Pro Tip 1/3Caution Advised
Use 'overhasty' to suggest that someone should slow down and reconsider their actions. 
Perhaps you are being overhasty in selling your house without a proper plan.
Pro Tip 2/3Negative Outcome
'Overhasty' often implies that the quick action will lead to negative results. 
Her overhasty decision led to a failed project.
Pro Tip 3/3Emotional Impulse
It can imply that emotions overruled logical thinking, leading to a speedy but unwise action. 
Don't let your excitement result in an overhasty agreement.