The SCOM console has a built in task that you can run to determine if any rules or monitors failed to execute for a particular agent. You can run this as follows:-
1. Open up the Monitoring Node of the console
2. Open up the Operations Manager folder, then open the Agent folder within
3. Click on Agent Health State and search for your agent in the Look For field of the Agent State column
4. In the Actions pane (click on Actions on top toolbar if you cannot see this) choose the following Health Service Task:-Show Failed Rules and Monitors for this Health Service.
5. Click on Run to run the task