Are you talking about when swapping with winter tires or the car just loses its TPMS connection? I had the latter about 3 or 4 times over the years and Tesla has fixed it every time under warranty for free. Each time they made some noise about upgrading or fixing the antennas use to hear the sensors. Hasn't happened yet out of warranty.
But to answer your question, the tool will allow you to "pair" the sensors with the car and to tell the car which sensor is on which wheel. You can call it resetting or programming or whatever.
I don't believe the tool is available any more for purchase but a few folks here have them. Maybe you could borrow one?