No, the contractor does not need to document the maintenance of the equipment. Provide a total inventory of the contractor's equipment (this could be a list, copies of the manufacturer's info, or anything showing the type of equipment they use and power source. Of course, the inventory is just a snapshot in time. Ensure that substitutions are also electric.
Question
If all of the onsite landscaping is done by a contractor that only uses 100% electric equipment does the contractor need to document the maintenance of the equipment for the credit to be achieved? They have many items that are the same and so they do not keep track of which specific mower was brought to the site, for example.