I think maybe the only card in Magic that can really get away with having no rules text is [[Counterspell]]. Possibly the only one whose name actually explains what it does more succinctly than the rules text.
@Evu Most instants and sorceries get away with it. Particularly any that do one simple thing:
* Lightning bolt
* Wrath of God
* Rampant Growth (although is it basic or a basic type, is it tapped question abound)
etc.
Cryptic Command was a terrible choice.
Permanents with relevant text in play aren't good options. And those can just be done with minimal text boxes, those look good.
I mean, I know what Lightning Bolt and Wrath of God do because I've been playing Magic for a long time. But I wouldn't fault anybody who doesn't remember whether Lightning Bolt deals 2 or 3 damage, or what the second sentence on Wrath of God is, etc.
Agreed about Cryptic Command. If my life depended on it I could maybe tell you one of its modes.