If you have garage keepers insurance, your tools are covered. If you are working on other folks' cars without garage keepers insurance, you are playing with fire.
The only requirement for your insurance to cover your tools (if you have garage keepers insurance) is to inventory your tools periodically, once a quarter is more than often enough.
I pay $750 for a year's worth of garage keepers insurance that covers liabilty for work I do on others' cars, shop insurance and my tools. Max coverage, $1 mil liability, $50K on customers vehicles.
FWIW-my mother used to own a truck shop. None of her employees would inventory their tools. When the shop got busted into, they all whined and mother told them the next time she asks for an inventory before the fact, you'd better give it to her. The mechanics got a list of tools and purchase dates from the Snap-on guy-the insurance company refused as it was dated after the date of loss and the policy specifically requested inventories.
Insurance only works when you have it and understand it.
Peace,
Paul