The general problem with Alexa and skills (and really with voice interfaces generally) is that the voice recognition has gotten pretty good but conversational speech understanding really has not. As a result, commands are sort of like a wizard's incantation (or a CLI). You have to pretty much nail the exact syntax you need and there is very limited discoverability. That's fine for a few things but remembering syntax for a bunch of different seldom-used skills quickly breaks down.