If you did bind the plugins to the Designer events.
For entity names.
The name will be automatically singular when you add a new entity, otherwise you'll need to manually rename the entity.
That's because that's a System plugin not a Direct Runable plugin, so you can't run the plugin yourself, rather it should be hooked with some Designer events.
If you want you may, modify the plugin (source code comes with the SDK), to change its type to DirectRun.