Pre-nuptial agreements

Many people who are wealthy would want to sign a prenuptial agreement to sort of exclude their assets from their marriage. Does bringing it up create any acrimony or mistrust before the ceremony? I am sure you are saying hey let me put some safeguards in place first so that should any issue arise there would be very little alimony to you know…… . What are the key clauses to look out for before signing a prenuptial agreement??