Using Terraform to create a cloudwatch alert (metric_alarm). How can I use alarm_actions for an individual host?

The Terraform documentation covers cloudwatch alarms in the context of autoscaling groups, but not individual instances.

resource "aws_cloudwatch_metric_alarm" "foobar" {
  alarm_name                = "terraform-test-foobar5"
  comparison_operator       = "GreaterThanOrEqualToThreshold"
  evaluation_periods        = "2"
  metric_name               = "CPUUtilization"
  ...
  dimensions {
    InstanceId = "${aws_instance.myOrg-myHost.id}"
  }

  alarm_description = "This metric monitors ec2 cpu utilization"
  #This would be for autoscaling
  #alarm_actions     = ["${aws_autoscaling_policy.bat.arn}"]
}

I'm guessing it will be something like:

alarm_actions = ["arn:aws:sns:us-east-1:111122223333:MyTopic"]