In the scrum guide, the scrum master is considered to have a management role. Although it's a management role, I don't believe it's a people management role. That's what the Engineering Manager does and ideally they wouldn't be attending the scrum.
We fought that battle and lost
But anyway my point was that he does a bad job at communicating what he does for us.
I had a scrum master that literally did nothing. He tried to get me to do his work, like running planning poker, updating sprint status slides, and other assorted nonsense, while he literally phoned it in from his kid’s baseball game. I was the tech lead on the team and flat out refused. Eventually he got one of the more junior engineers to do it.