If a person negotiates or delivers a document of title for value, otherwise than as a mere intermediary under § 7-508, unless otherwise agreed, the transferor, in addition to any warranty made in selling or leasing the goods, warrants to its immediate purchaser only that: The document is genuine; The transferor does not have knowledge of any fact that would impair the document’s validity or worth; and The negotiation or delivery is rightful and fully effective with respect to the title to the document and the goods it represents.