The move functions as a counterattack, hence the name. When used, the Brawler takes a defensive stance with their hands covering their face, similar to Little Mac when he uses Slip Counter. If not hit, the Brawler goes through a small period of endlag, but if they are hit, a heartbeat line icon will appear above their head, and the Brawler will proceed to grab the opponent and slam them onto the ground behind them, damaging anyone else who might be nearby. Afterwards, the countered opponent will bounce off the ground and be sent reeling, though the distance the opponent flies will depend on how much damage they have taken thus far.
Counter Throw is unique in many ways: it is actually very fast for a counter, allowing it to be spammed due to its low ending lag, though this is compensated by the move's shorter counter window. It is also tied with Gut Check for having the second highest damage multiplier out of all counterattacks, at 1.5x (only Tetrakarn is higher, at 1.6x). However, it has multiple flaws: since the counterattack is a grab, the opponent must be within close range to be grabbed; attacks from below soft platforms or moves with a long enough range (most often disjointed hitboxes) will outrange the grab, causing it to miss. Additionally, the counter will not counter anything that hits the Mii Brawler's feet, and completely fails against projectiles (such as Charge Shot), which causes the Brawler to take full damage and knockback.
As a result, Counter Throw is a low-lag option that allows the Brawler to heavily punish enemy mistakes, but is very inconsistent due to its flaws. It can be considered a "high-risk, high-reward" counterattack due to its speed, power, and inconsistency.