Most homeowners policies cover "personal use" tools as a part of the contents coverage up to the amount of contents coverage on the policy (typically 75% of the amount of coverage on the home). Business use of any item makes it then subject to a special limit for "business personal property" that is usually very small ($200 most policies). Incidentally - personal property is covered anywhere in the world, but normally limited to 10% of the amount on the policy when away from home.
What Peter is describing is "Commercial Inland Marine" coverage, which can be written on a "blanket" basis, or "scheduled" - some companies limit the use of blanket policies. The idea is to insure large expensive items on a scheduled basis, and write a small blanket for hand tools, etc.
Most companies that write homeowners insurance will write it, especially if you have informed them of business use of your vehicle, and they are insuring it that way (by the way - if you are using your personal truck or van for business purposes and HAVEN'T informed your agent you may lose your auto insurance entirely if you have an accident with that vehicle and they find out after the fact that you are using it professionally. And you don't want to be shopping for commercial auto insurance AFTER you've had an at fault accident).