The sale of property is entirely contractual and thus the agreement of purchase and sale is the document which governs the rights and responsibilities between the parties. It is imperative that  your agreement  be carefully drafted and reviewed prior to being finalized so as to minimize risk and avoid unwanted and often expensive obligations. Sellers often are unsure about  what information should be disclosed to a buyer. There is no general duty  to disclose anything about the condition of your property. You cannot conceal defects which  would be discoverable by a purchaser on an inspection. Does this mean that a water problem in your basement three years prior must be disclosed for fear of being sued after closing? It depends. If the problem was discrete and you repaired it and it has not  been a problem since , my view is that this was a repair made by a prudent owner.  On the other hand what happens if water penetrates your basement three weeks prior to listing your property for sale.?  Are you in jeopardy of being sued for concealment of a defect ? Thus the question, is it a repair in the ordinary course of owning a home that occured at an inoppurtune time? or was it something sinister where the homeowner only did the repair so the new purchaser would not find evidence of water penetration. This is sometimes a tough call and the stakes can be high if you end up being sued. 

It is wise to consult a solicitior before you list your property to determine the precise legal description which is to be used in the Agreement of Purchase and Sale. Agents are often not equipped and lack  the legal training necessary to ascertain with precison the legal description of your property.