Prompt library starter

Why a library beats remembering

A good prompt is a small piece of engineering: you found the wording that gets the answer you want, first time. Typing it fresh each time throws that work away — and the from-memory version is always a little worse. The fix is the same one programmers use for code they reuse: keep it, name it, note when it applies. A card in your library needs four things, and only four.

Card one — rewrite for the reader

For when the content is right but the register is wrong: too stiff, too casual, too internal. The 'flag what you did not change' line is what makes it safe — it stops the AI helpfully rewriting your facts along with your tone.

Rewrite the text below for a customer who has never dealt with us before. Keep every fact, figure and commitment exactly as it is — change only the tone and the clarity. Plain words, short sentences. At the end, list anything you were tempted to change but left alone, so I can check whether it actually needs changing.

Card two — summarise for a decision

Most summaries fail because they summarise the document instead of serving the reader. Naming the decision turns a book report into a briefing.

Summarise the text below for someone who has to decide whether to renew this contract for another year. Lead with what matters most to that choice, then set out what argues each way. End with what is missing — anything the document does not say that the decision-maker would want to know.

Card three — first draft from rough notes

The blank page is the AI's best use and its most dangerous one — it will happily fill your gaps with plausible inventions. The [ASSUMED] marker keeps the inventions visible.

Turn the rough notes below into a first draft of an email to the team about the office move. Keep my order unless something clearly belongs elsewhere — and tell me if you move it. Where a note is ambiguous, choose a sensible reading and mark it [ASSUMED] so I can correct it rather than miss it.

Card four — explain unfamiliar material

For contracts, reports and anything technical that landed on your desk from someone else's field. The 'common misunderstanding' line is the quiet gem — it is where the real danger in unfamiliar material usually lives.

Explain the text below as if to a colleague who is clever but new to the subject. Define each term the first time you use it. Finish with the three things most worth remembering, and one thing people commonly get wrong about this topic.

Card five — check it before it goes out

The reverse of writing: reading your own draft through the recipient's eyes. Asking for the smallest edits, not a rewrite, keeps your voice in the result.

Read the draft below as if you were the person receiving it. What is unclear on first reading, what could land badly, and what question will they immediately come back with? For each, suggest the smallest edit that fixes it — I want repairs, not a rewrite.

Growing it without killing it

The failure mode of every library is bloat: forty prompts you never open are worth less than eight you trust. Three habits keep it alive.

1. 1Add a card only after a prompt has worked twice. Once is luck; twice is a tool.
2. 2When you improve a card mid-job, update the library the same day — the improvement is the asset.
3. 3Prune quarterly: anything you have not reached for since last time gets deleted. If it was really good, you will rebuild it better.