aurora_admin syntax error messages have incomplete syntax

If I run

aurora_admin host_drain --hosts=myhost

I get the error

FATAL] usage: host_drain {--filename=filename | --hosts=hosts}

see the help subcommand for more details.

This is missing the need to pass in the cluster name. If you look at the help, you'll see cluster is there but on the next line which is probably the issue. host_activate/host_status have the same issue, and there's probably others