Too clever, etc. by half
Definition 1 of 1
Pro Tip 1/3Negative Nuance
Implies disapproval of someone's actions as being overly clever or shrewd in a cunning way. 
His plan was too clever by half and ended up backfiring.
Pro Tip 2/3Annoying Behavior
Used to describe someone causing irritation because they overcomplicate things unnecessarily. 
She's too clever by half with her constant, needlessly complex suggestions.
Pro Tip 3/3Irony Alert
Often used ironically to point out someone's failed attempt to be clever. 
He thought he missed the questions on purpose, but that was too clever by half.