A login must have authority over some database roles in the msdb database in order to access SQL Server Agent. These roles in the msdb database are as follows.
If a login is authorized in any of the above database roles or if it is sysadmin, it can see SQL Server Agent on SSMS. Let’s explain these roles.
SQLAgentUserRole: This role is the least authorized role of the SQL Server Agent database roles. The following table that I have copy from msdn shows the operations that a login with this role can do. For detailed information about operators and proxies, please refer to the following articles.
SQLAgentReaderRole: This role has the full authority of SQLAgentUserRole. There are some extra privileges. You can see the details in the following link.
SQLAgentOperatorRole: This role has the full authority of SQLAgentReaderRole. There are some extra privileges.
You can see the details in the following link.