I used to be a crew chief in US Air Force, so many years ago. All of our tool boxes were foam lined and every tool from a speed handle to a socket had to be in the toolbox when you left the flight line or every plane you worked on was grounded until the tool was found. The tools were etched with the box number too!
Very few tools were ever lost, but sometimes the system broke down and a missing tool was overlooked when returned to supply, speed bits could drop easily into a panel and because the color matched the foam could easily be overlooked on check in. The next person to open the panel usually found it.
Once an engine specialist returned a box that had a missing tool and the entire engine was taken from the plane and sent to engine repair to be disassembled.