Unfortunately it's
very hard to come up with an exact set of rules which in the end reinforce the exact kind of social contract you're looking for. There's a couple of things to make this even harder:
- There are people who enjoy, and enjoy playing against, such lists. (Yes, the idea of the format didn't start that way, but there are sections of the community that enjoy it that way.) If the rules were written to exclude that playstyle, the format would lose a good chunk of players
- There's a saying in Roleplaying games that goes along the lines of "if you give it stats, that means we can kill it". If you have a God in your game and just say "It's a God. You can't kill it" then the players will - for the most part - believe you. If you give it stats, no matter how outlandish those stats are, they'll find a way to kill it. Same thing here; if you just say "it's a social format" most people - again, for the most part - will believe you and play it that way. If you start giving it "stats" - which is to say, rules, the exact types of players you're talking about will point to the rules and say "it doesn't say I can't do <x> so that's what I'm going to do" (see: a lot of discussions about the banned list).
TL;DR it's way harder to specify exactly what "social contract" means in words, and even if you do, it just gives the rules lawyers something to figure their way around.
Edited to add: By far the best way to approach this is find a group of players who think the same way you do, sit down and agree on the way you want to play the game, and have fun with it that way.