I use it for breading fish as well
A "breader" is a device that is used to assist in "breading" something, usually food, usually prior to deep frying. You absolutely *could* put toast in a breader, the question would be "why?"
https://www.amazon.com/Cooks-Choice-Original-Breader-Breading/dp/B000IN0KUO
https://www.amazon.com/King-Kooker-1113BK-Breader-Box/dp/B0767SRYP2/
these are a thing too - sporting goods stores have 'em for battering fish.
https://www.amazon.com/Cooks-Choice-Original-Breader-Breading/dp/B000IN0KUO