Monitoring the Environment
SQL Server Agent monitors itself and the Microsoft® SQL Server™ service.
Self-Monitoring
SQL Server Agent starts the xp_sqlagent_monitor extended stored procedure (SQL Server Agent Monitor) to monitor the SQLServerAgent service to ensure that it is available to execute scheduled jobs, raise alerts, and notify operators. If the SQLServerAgent service terminates unexpectedly, the SQL Server Agent Monitor restarts the service.
Restarting the SQL Server Service
SQL Server Agent can restart the local instance of SQL Server if it has terminated for reasons other than a typical shutdown. Automatic restart is enabled by default. SQL Server Agent restarts the instance of SQL Server when it detects abnormal termination. This allows an alert to be set on this event.
Note If you are using SQL Server 2000 failover clustering, you must ensure auto-restart is disabled in order for failover clustering to work.
To set job execution shutdown