Contracts can read alike on the first page and still cover different equipment. The covered list is where that difference usually hides, and it only helps you if you know what your house actually contains. Before you open a provider's page, write your own inventory.
Start with what your house contains
Walk through the home room by room, and include the utility spaces, attic, and garage. Note each major system and appliance you would be upset to lose: heating and cooling equipment, water heating, the range, the refrigerator, the dishwasher, the washer and dryer, the garbage disposal, the garage door opener, and any well or pool equipment you have. For each one, write the make, the model, and the approximate age from the nameplate. You will need this on the phone with a provider, and it is far easier to gather now than during a breakdown.
Read the covered list as a list, not a summary
Summaries on sales pages tend to say that major systems and appliances are included. The contract is more specific. Look for the schedule of covered items, and check whether each item on your inventory appears by name or falls under a general heading. Pay attention to words such as 'including' and 'such as,' which can mean the list is a sample rather than a complete set. Ask the provider in writing whether the list is closed.
Match the two columns
Put your inventory beside the covered list from each contract you are considering. Mark three kinds of result: items named directly, items covered only under a general heading, and items you own that appear nowhere. The last column matters most, because it shows what you would still pay for on your own. Keep the marks short so the sheets can be compared at a glance.
Sheets rarely line up perfectly, so note where the differences fall. A contract that names a system precisely may leave out a related part. A contract that uses a general heading may still leave the item in question for the provider to decide. Neither result is a verdict on quality. It is a question to put to the provider before you sign.
Where the figures live
This is a list-matching exercise, so it does not need a price to be useful. When you are ready to see the published terms side by side, the home warranty companies compared, term by term page lays out the same fields for each company. Where a sample is available, read the sample contract before you buy, since the covered list is often near the front of the agreement or in a schedule at the back. The methodology page explains how this site gathers its figures.