I agree with most of the answers given. I would add the following considerations.
If possible, get the NDA to include a time limit. This is typically 1 to 5 years. I explain to clients that I want to take their needs seriously and do not want to agree to something that I cannot uphold. I get worried about keeping secrets longer than 5 years just because they become absorbed in general knowledge and can therefore become part of conversations with others.
Request that all information that is to be considered confidential be marked confidential. Further, request that any information that is transmitted by non-written means and is confidential, be followed up by a written note that says x and y in the conversation of such and such a date was confidential, and that the note be delivered not later than about a week after the conversation.
The NDA should include terms that state that information each of you receive through other means, providing that those means do not violate an NDA, is not confidential information.
I do think that some very general description of what areas of work are being discussed probably does belong in the NDA. Something along the lines of: " the parties wish to work together on a development of xxx and to share information on it". Otherwise it is just too vague.