Comments in arc diff

It would be nice if there was a way to add a comment when you run arc diff that isn’t part of the commit message. You can do it by running arc diff then going to the URL and using the form, but it would be a lot more convenient if you could do it from the command line interface.

I’m thinking something like:

Comment: I think this is the right way to do it. What do you think? Should I do X instead of Y?

I don’t really want stuff like that in the commit message.