I love this concept. I always begin messages with the most actionable or important thing at the top, and the rest that follows is the context. Respect the time of others and don't bury the lede
You see this all the time in business proposals. Executive summary at the top, typically 2-3 paragraphs max. Manager summary, 1-2 pages. Engineer detailed overview, 3-10 pages. Anything else is an addendum.