using a sledgehammer to crack a nut; overkill
A four-character idiom meaning to use excessive force or a grand-scale measure for a trivial matter. Often used critically when someone overreacts or employs disproportionate means.
I want to avoid an overkill response to a small mistake.
His plan seems like using a sledgehammer to crack a nut.
This is the full classical phrase from which 割鶏牛刀 is derived. It is more explicit and less compact, but carries the same meaning.
A common word meaning 'exaggerated' or 'overblown'. Unlike 割鶏牛刀, it is not limited to disproportionate means and can refer to any kind of exaggeration.
Derived from the classical Chinese phrase 牛刀をもって鶏を割く (using an ox-cleaver to cut up a chicken). The idiom is a compact four-character abbreviation of that phrase.