It's amazing to me that someone's whole job could be running the scrum board, and that such a person would be questioning other people's contribution to the team.
I've had a really good scrum master. (Plenty of bad ones too). The really good one I could say something like
"I started work on this item and realized that I'm actually missing a lot of context and information in the requirements. I need your help clarifying them"
The scrum Master knew who to contact to get that information would set up a meeting, have the meeting without me if they thought they could do it or schedule it and include me so I could ask the questions I needed, Mark the ticket for me as blocked, fill out the info after the meeting and communicate the risk and reason for delay to stakeholders.
Basically I could say "There's a problem!" and the scrum Master would get it taken care of or find someone who could. Probably the most valuable person on that team.
I'm not sure it is a larger scope, I've always understood this to be their role - they lead scrum meetings, but outside meetings they were the one that helped get the team unblocked. Managing the board was just a side-effect of keeping an eye out for any team members who were stuck.
On top of that the one I worked with who was good at this also took on small cases because otherwise he'd regularly have nothing to do.
"I started work on this item and realized that I'm actually missing a lot of context and information in the requirements. I need your help clarifying them"
The scrum Master knew who to contact to get that information would set up a meeting, have the meeting without me if they thought they could do it or schedule it and include me so I could ask the questions I needed, Mark the ticket for me as blocked, fill out the info after the meeting and communicate the risk and reason for delay to stakeholders.
Basically I could say "There's a problem!" and the scrum Master would get it taken care of or find someone who could. Probably the most valuable person on that team.