A brief description of the problem we're trying to solve. Why is this valuable to work on?
A sentence or two of the problem and the proposed solution.
A list of the things we hope to accomplish with this solution
A list of things that we are explicitly calling out that will not be accomplished with this solution.
Describe the impacts that this will have on the product. Are there already existing things within the product that will need to be changed/updated because of this?
A description of ideas considered that may come into consideration in the design / implementation, or in future.
What are the expected changes we expect to see based off of this. What metrics can we use to measure the impact of this solution?
What criteria must be met in order to consider this project done and a success?
As a user, I want to do a thing so that I can be a happy user (FYI: http://www.writeauserstory.com/)