We have a saying in our firm that smooth transactions make successful transitions. Basically, if two parties cannot agree on the elements of the LOI, they will probably have a hard time negotiating while dealing with the minutiae of the purchase agreement. Normally, once the key points of the deal are negotiated up front, the rest of the transaction tends to work much more smoothly.
A confidentiality agreement puts each party on notice that what is being discussed is solely for each party and only for the stated purpose within the agreement. The critical elements within the confidentiality agreement are therefore that parties must specifically state the type of information that is being disclosed and also the intended purpose for which the information is to be used.