Get the Short Version of a Long Document

Say what the summary is for

"Summarize this" gets you a summary, and it is nearly always the wrong length and the wrong shape, because the useful version depends entirely on what you are about to do. Name that part instead, and the rest follows on its own.

Deciding whether to read it: "In three sentences, what is this, and does it need me?" Walking into a meeting about it: "The five things I will be asked, with the page each one is on." Chasing one thread through a long file: "Everything on the renewal date, nothing else." Passing it along: "A paragraph for someone who has never seen this document."

Length behaves the same way. Ask for five bullets and five is what arrives. Ask for a sentence per section and you get the document's own outline back. The version that reads worst is the one nobody specified, which lands somewhere in the middle and is often long enough to want summarizing again.

What a summary drops, and how to get it back

A summary is a pile of decisions about what matters, made by something that has not sat in any of your meetings. It keeps what documents are usually for: what got decided, what is being recommended, who owes what, what changed since last time. It drops background, hedging, and the third example of a point already made twice.

That is right most of the time and wrong in the one way that costs you, because the sentence that mattered to you was, to anything reading it cold, a detail. So say what you care about in the same message: "Summarize this, and separately give me everything it says about indemnity." Now it is not a judgement call.

Two habits are worth keeping. Ask what it left out, which is a question with a real answer and often more interesting than the summary. And when a figure is load-bearing, ask which page it came off and go and look, especially if the file is a scan.

What it opens, and the three things that stop it

Word files, both DOCX and the older DOC. PDFs. Slide decks, where the words on the slides and the speaker notes underneath both get read, which matters because the notes are usually where the argument actually lives. Plain text, rich text, ebooks, a web page saved to a file.

Three things stop it outright. A link to something in Drive or SharePoint is not a document: there is no account connection, so download the file and upload that. A PDF sealed with a password stays sealed until you supply the password. And a scan with no recognized text behind it is a stack of photographs, which can still be read, but the words go through recognition first and recognition is where a 3 becomes an 8 in a column of figures.

Where length actually costs you

Nothing rejects a file for being long, but length is not free either, and anyone claiming otherwise has not summarized three hundred pages. Text is taken in stretches of roughly two thousand lines, forty-odd pages of ordinary prose, so a document past that is covered in several passes rather than held in view all at once.

What that does to the result is specific rather than general. A scoped request survives it intact, because "everything on indemnity" is answered the same way on pass four as on pass one. A single summary of the whole thing is where it shows: the passes are even-handed, so a long report comes back flatter than a person would write it, with chapter nine weighted like chapter two even though chapter two was the one that mattered. The fix costs one sentence. Ask for a summary per section, read the section names, then ask for depth on the two that earn it.

When a summary is the wrong thing to ask for

The tell is whether your question has a quotation or a number at the end of it.

If you need one clause and its exact wording, summarizing is a detour: put the question to the document directly and ask for the page. If the file is a workbook with formulas across several sheets, the answer is a recalculation rather than a paragraph. If it is an export from your bank or your CRM, what you want is a total or a grouping, and prose is the least useful shape that could arrive.

Summaries earn their keep in the other case, the one where you do not yet know what you are looking for and need to find out cheaply whether it is in there.