A tournament token (Abbreviated as TT) is the most valuable currency in the game, because it can unlock the best kits in some minigames. A classic example is the walls, where this currency can be used to buy 5 kits. Furthermore, this currency cannot be used on a lot of things, and can only be earned while in a tournament. Tournaments are very rarely hosted, and each tournament has a token limit, due to which the currency remains very rare and valuable. They are now only useful in The Walls and Quakecraft.
Since The Walls and Quakecraft update, Tournament-specific items/kits are buyable by regular Coins, making the TT useless (and probably removed)