Tools Ardupilot

Hi, i just want to ask what is the main use of Tools directory in ArduPilot. I read something on the docs, and also tried something. I am working with UWB Pozyx, and noticed that there is a specific Tools file with the code that should run on the Arduino board. Is is there just for being copied? It seems to be that it is not “called” in any part of the flight controller code. Thank you for any help