Essentially.

[Mostly, they're left to their own devices. But when it comes down to it, the Tetherer is one of the ones in charge of their fates.]

I Tether worlds to the Nexus so that we may travel to them and also keep a link from which we may keep track of them, a system worked out by Tetherers before me. I can also undo the Separation of worlds, or Tether new worlds into new wholes. I can transport anything anywhere through a Tether.

...Here, I am much more limited.