/*
	For users that have a need to administer jobs through the SQL Agent
	this script effectively makes them Agent Admins

	It assumes that the login is already on the server
*/

declare @login_name sysname = '<login_name>'

USE msdb
if not exists (select 1 from sys.sysusers where name = @login_name)
begin
  exec sp_adduser @loginame = @login_name
end
exec sp_addrolemember @rolename = 'db_datareader', @membername = @login_name
exec sp_addrolemember @rolename = 'SQLAgentOperatorRole',@membername =  @login_name
exec sp_addrolemember @rolename = 'SQLAgentReaderRole',@membername =  @login_name
exec sp_addrolemember @rolename = 'SQLAgentUserRole', @membername = @login_name