When you are setting up alerts using WMI and if your intention is to capture the event data with sql agent job make sure you change below settings in SQL Server Agent Configuration.

or

EXEC msdb.dbo.sp_set_sqlagent_properties @alert_replace_runtime_tokens = 1
GO

This will allow SQL Server Agent to replace the tokens with running values (what database changed, who changed it etc.). Read more about using Tokens in Job Steps here (make sure you read the security note in the article and understand the security risk).