You can do it either way, it will be valid as long as the signatures are valid...
The thing is that if, god forbidden, things turn ugly someday, and you end up in the court...lawyers in both sides would try as much as they can using all kinds of theory to invalidate the contract...
so, if I were you, I could write in agreed value of house, accounts etc, just in case, someday there were a fight, and the contract were invalidated, as least, each of you still could keep the value wrote in the contract...because they are values before marriage, therefore, by definition, separate property...
In community property states, the default is: if you cannot track the value as the seperate property, it is community...therefore, setting a value now will at least give you a baseline to work on, just in case, in the future...
some lawyers will take on different position on the issue...you will just have to decide what is the best for yeourself..