Roles help in maintaining security in all components of SQL server.

To configure SQL Server job agent fixed server roles, we need to navigate to msdb –> security –> roles –> DB roles.
SQL agent roles:

SQLAgentUserRole : Ability to manage Jobs that they own

SQLAgentReaderRole: Has additional rights than SQLAgentUserRole and also to monitor multiserver jobs

SQLAgentOperatorRole: SQLAgentReaderRole rights in addition to modify operators, proxy and alert. Delete job history and modify the schedule of local jobs.