My homeowners ins only values the garage at a percentage of the house value.
There is a set percentage of that evaluation for the contents. In most cases you can value add to the policy but there are limits. You can however get an insurance policy for the tools as a separate policy. I doubt your home owners policy will cover your entire lose, possibly none if it is an outbuilding...
Incorrect, at least in all my dealings with insurance companies.
Yes, your outbuildings are typically valued at a percentage, typically 10%, of your "principal residence". You can, and probably should, add to that number as needed. If your house is valued at $200,000, you will be paid for up to $20,000 worth of repair or replacement whichever comes first. Construction materials are covered at 90% until you show receipts for replacement.
The contents of your buildings are covered under "personal property" according to your policy limitations, either a set amount, or full replacement value.
In the case of my insurance company, you make a list, on the provided forms, of lost or damaged items, including the replacement value from whatever source you can come up with. You will initially be paid 90% of the value listed, and the final 10% when you show receipts for the replacement, if you chose to do so. If you choose not to replace the individual items you will lose that 10% on each one.
Vehicles are covered under their own policy whether they are inside a building or not. There is typically no coverage for unlicensed vehicles, but that varies by insurance company. My father got paid for a tornado damaged unlicensed jeep that was used as a farm vehicle just like it was personal property.
