A first-sentence direct answer wins in AI results because grounded answer engines lift stand-alone quotable sentences into their synthesized responses — a full sentence stating the fact is retrievable and citable, while a bullet fragment or a lead-in paragraph forces the model to paraphrase, which reduces the odds it credits the source.
The mechanism is documented at a high level in each engine's public materials. Perplexity's FAQ describes citation of retrieved sources. Google's AI-features documentation describes AI Overviews as generated on retrieved passages from the web index. In both cases, a passage that reads as a complete claim is easier to attribute than a fragment that requires context reconstruction.
Editorial pattern: for every H2 question heading, the immediately-following paragraph should open with a full-sentence answer using named subjects — "IndexNow is an open protocol…" not "It's a Bing-backed protocol…". Vague pronouns kill attribution; the retrieval passage often gets shown to the model without its parent context.
Match the schema. The acceptedAnswer.text field in QAPage/FAQPage should mirror that same first sentence. This is not duplication — it is telling the crawler and the model the same thing in two channels.
Reserve nuance and caveats for the following paragraphs. The first sentence carries the citation weight; the rest of the page explains, sources, and links.