What makes a yo-yo "built for competition"?

Maybe the question is: what makes a yo-yo a “non-competition” yo-yo?

While we all may argue the fine points of what makes a “competition” yo-yo; what do we make of a yo-yo that is described as generally “not being a competition yo-yo”?

I think that description says way more than one that calls it a “competition” level yo-yo.