As I've found, you need to do the work and describe it completely, so that you have a basis for answering questions and making (or refusing to make) changes, but then you need an executive summary for the boss (and legal and the public if a draft document must be circulated) leaving most of that out, a one-pager for his/her boss, an elevator pitch for the *EO (might be a deputy or tech area exec officer) or agency chief/deputy (given modern tendencies toward micromanagement), and a short paragraph sound bite for the PR person who will talk with the press and politicians. The final decision, unfortunately will at best be made based on the one-pager, and often just the sound bite or elevator pitch. That doesn't relieve a functional professional from the need to do the work.