To clarify, I'm not talking about the talkback accessibility feature. I mean when the assistant annoyingly TELLS you what it's doing as opposed to just doing it (e.g. "Opening: Hulu").
Like, I'm looking at a giant screen and just said the name of an app. I don't need you to TELL me (in an obnoxiously loud voice, btw) you're opening the app, just f*cking open it
From your phone, go to assistant settings, then assistant voice & sounds> speech output & select "none"/ "hands-free only".