add a tag for CW alert

aince

I have CW to JSM integration in place and by default CW alert doesnt have that tag field. I would like to update alert once its created with adding tag and getting the keyword from description. 

I am looking a solution within JSM(Opsgenie) there is an automation but that doesn't include alert field updates. and i dont want to create another lambda function do this.

Is there a way to add tag for CW alerts or other any alerts that doesnt come with tag in first place using JSM automation or policies.

thanks.

aince

it is done with simple policy, having syntax issue