using play command without args connects the bot to the vc.

[ZeNyfh]

[9382]

The command state checks take place before any sort of argument check by the command logic, so that'll be why it joins. Radio actually gets around this by implementing the "can join" check later manually (see its code), which I implemented for that since it had a valid 0-argument case. If it joining despite no good args is something unwanted, then take a look there