Acres of Area..... or Inches of Indefinite Boundary

In the past week or so, I have encountered two separate instances in which properties were casually (think casual friday) described by realtors, seller, buyers and others in terms of acres.  In one instance a 38  acres parcel turned out to only have 35 acres.  In another instance, a potential buyer wanted to make an offer on a home on three acres only to find out that the land included with the home was sitting on a one acre parcel and the other two acres had a separate legal description.  The potential buyers were unsure what one acre, two acres or three acres looked like.  To be honest, estimating acreage is difficult, at best, without the benefit of recorded distances associated with the property.  Secondly, just because a legal description has been confirmed to contain one acre, it is difficult to convey that information, over the phone per se, to a realtor or buyer standing in the backyard.  If the confirmed one-acre legal description isn't verified on the ground to see, the buyer and/or realtor might assume the fence line is the edge of the one acre parcel when in fact it isn't.
Clear as mud right????  Here's the surveying tip of the day.... when acreage is involved, consult with your local neighborhood surveyor and discuss comparing the legal description with the acreage.  Secondly, avoid putting the acreage amount, correct or not, in the contract.  Use the specific language of the legal description.