Restrict Team from Commenting on issues with visibility to customer

[Mayssam Ismail]

how can i prevent a specific agent to comment to customers on issues.

[Andy Heinzer]

When you invite a user to become an Agent in a project, this adds that user to the project role called Service Desk Team.   Any user in that role of a Service Desk project has the ability to reply directly to customers.   So if you don't want to completely remove this user from their Agent role, you could just remove them from the project role. 

But this would prevent them from being able to respond to the entire project.   I'm not sure if that is a helpful suggestion or going too far in your case. 

It might also help to review the Setting up service desk users in order to make sure you understand the different roles users can have within Service Desk.