Tongo isn’t a fully fleshed out game, and the writers didn’t have anything concrete to go on when referencing it. It was written as a mashup of poker, mahjongg and craps.

There were never any “official” rules established; according to Ron D. Moore the writers had only a vague idea of what the game was actually about, and mostly just made it up as they went along.

https://memory-alpha.fandom.com/wiki/Tongo