Most clients even if they mediate their divorce will benefit from having their own private attorney review the proposed agreement and suggest modifications. The quality of divorce mediators is very diverse so I never know until I see the proposed agreement whether it will be comprehensive, fair and clearly drafted. Some divorce mediators are attorneys and some are not. If the mediator is an attorney they are authorized to draft the agreement. If the divorce mediator is not an attorney, the parties will be referred to an attorney who will draft the agreement based upon the mediator's notes or memorandum.
Even where the mediator is an attorney they will almost always suggest that you obtain your own independent review by an attorney whose loyalty is solely to you. An experienced divorce attorney will immediately know if the agreement appears to be well written or whether it will need much work and revision.
There are many different ways to express provisions in an agreement and most clients, since they are not attorneys, will not know what the alternatives are. Therefore, what may sound good on paper may not be complete or perhaps should have been drafted in a very different manner. For example joint custody language can be very brief but really should not be. There are numerous provisions that should be included beyond merely saying the parents will consult with each other regarding decisions affecting the children. The drafing of child support and college provisions are important as is the decision whether to contribute to extra-curricular activities, which often is not a requirement.
An experienced divorce attorney will help you conclude with a clear agreement that is less likely to be challenged in the future due to missing provisions or unintended consequences. At a minimum, people using divorce mediators should obtain an independent review prior to signing the agreement.