What the comparison takes apart
Each quote's schedule is matched against the equipment list you gave, so a missing item shows as a row. Then the blanket small-tools limit and per-item cap, the valuation basis, the deductible, the rented and borrowed limit, installation floater coverage for materials on site, and conditions such as theft from unattended vehicles. The cheaper quote with half the schedule is visible as exactly that.
Keeping the schedule honest
Add equipment when you buy it and remove it when you sell it. Items not on the schedule above the threshold are not covered beyond the blanket cap. From the policy page, adding an item is a change request that goes to the carrier automatically.
Installation floaters
If you buy materials that sit on a site before you install them, an installation floater covers them until the work is accepted. Contractors who skip this discover the property owner's policy does not cover their materials. The comparison shows whether each quote includes it and at what limit.
After you buy
The equipment schedule lives on the policy card, certificates to general contractors show the coverage, and the renewal application carries the schedule forward for you to confirm.