On February 9, George Jackson and his neighbors, Karen and Steve Devenyn, drafted and signed a document that purports to convey a seventy-nine-acre parcel of land owned by Jackson. By the terms of the agreement, Jackson wished to reserve a 1.3-acre portion of the parcel. Although the agreement contained a drawing and dimensions of the conveyance, it did not contain a specific description of the parcel. Jackson died on May 8, and his estate refused to honor the agreement. The Devenyns then filed a petition with the probate court to order a conveyance. Based on the parol evidence rule, the estate of Jackson objected to the admission of the witnesses' testimony that they could point out the specific area based on conversations with Jackson. Explain whether the oral evidence is admissible.