The final walk-through addendum should always be included in a purchase agreement to give a buyer the right to walk through the property several days before title transfer to inspect it and ensure it is in the same condition (except for normal wear and tear) as when the purchase agreement was ratified.
I am continually amazed, as a listing agent, to see buyer's agents who do NOT include this addendum in their buyer's purchase offer. When I represent buyers, I always include it because I know and have seen first-hand the financial benefit to a buyer who is well represented by this addendum. Sometimes a buyer can save hundreds of dollars that would have otherwise gone unnoticed without this addendum.
A walk through is also the time for verificaton that all repairs were completed by the seller as agreed along with receipts for the work.
Real estate is serious business and a prospective buyer is well served when their agent is competent and looking out for their best interest at all times.