If a user is unclear of what the alarm is notifying they can review Preconfigured vSphere Alarms for definitions of automatically created alarms.
These alarms are not unique to VMC on AWS and will very commonly have a dedicated document further indicating the purpose for these alarms located at https://knowledge.broadcom.com/ or https://docs.vmware.com/
After review of the error, you may request the alarm to be reset via a support request or chat support.