A really bad way to find a missing torque wrench is to energize the equipment and wait for the arc blast. Tool counts help prevent such outcomes, but what if you can't find a missing tool? If you conclude your initial count was wrong but the tool is sitting across Phase A and Phase B bus rails, a disaster will follow.
Avoid this problem by breaking down the repair procedure into distinct stages. Count tools before and after each stage. For example, you need to remove a breaker so you can replace it. Once the breaker's out, count your tools. If one is missing, you have a good idea of where it is.
What if you accidentally kick a tool under something and can't find it? Prevent this — and other problems — by making a habit of putting tools in or on something, such as a bucket, tool towel, or cart, when they aren't in your hand.