For his first solo effort, David Lee Roth strips away the gonzo guitars that are Van Halen's trademark and accentuates his lounge-lizard-as-rock-star persona, resulting in an EP that succeeds because of that persona, not because the music is anything special.
Certainly, he doesn't add anything to "California Girls" and "Just a Gigolo/I Ain't Got Nobody" other than his joking, over-the-top vocals.
Then again, that's all he needs to do.