Must you list everything by item or can you simply say the contents of the house with special directions of certain items?

Yes, but having artfully drawn language in a will requires the services of a trained and experienced estate lawyer.  Do not try this on your own since doing so will definitely will result in a fight or a lawsuit when you are gone and someone has to interpret your layman's language.  This type of do it yourself task that end up in court.  Spend the time and money to get your will drafted correctly; it will be cheaper and better for all concerned in the long run.