Adding notes to a machine for the lifetime of a deployment

I’ve written a small tool that uses the maas CLI to deploy and release machines for some automated tests. I’d like to be able to tag or otherwise annotate the machines deployed by this tool so that it’s easy to differentiate them from nodes that have been manually deployed by the same user. I was going to use tags, but maas restricts tagging to admin users (which I can understand). Is there any other mechanism I could use?