This was [copied from package](https://github.com/Katello/katello-cli/blob/master/src/katello/client/core/package.py#L49) but I agree that it should say required unless repo_id is passed. I'll update that now.

Regarding repo_label, it would be nice but it's not on any of the other commands (package, errata, packagegroup). What if I open an issue to add it to every command?