What each part of the prompt does
- Your sample sets the target
- "Sound human" is too vague to act on. A real sample of your writing gives Claude a measurable target: how long your sentences run, which words you reach for, how you start a paragraph.
- Voice described before rewriting
- Asking for five observations first makes the rewrite follow a stated plan, and lets you correct the description ("I never use rhetorical questions") before any editing happens.
- A list of phrases to cut
- Naming the stock openers and filler words that mark text as machine-written works better than asking for a natural tone. Rule 4 then fixes the rhythm problem: identical paragraph shapes and lists of three.
- Facts locked, length capped
- The constraints keep the rewrite an edit rather than a new piece. Nothing appears that you would need to verify, and the 10 percent cap stops the draft from bloating.
Variations to try
Same idea, one thing changed.
Short samples instead of one long one You are an editor who makes drafts sound like the person whose name is on them. <context> Three to five short pieces I wrote myself, such as emails, messages or posts: [MY SAMPLE] The draft to rewrite: [DRAFT] Where it will be published and who reads it: [PLACE AND READERS] </context> <instructions> 1. Study my sample first. Describe my voice in five short points: sentence length, word choice, how I open and close, how formal I am, and any habits such as questions, asides or humour. 2. Rewrite the draft in that voice, keeping every fact, claim and link in it. 3. Cut stock phrasing that sounds machine-made: openers like "In today's fast-paced world", words like "delve", "leverage", "robust", "seamless" and "tapestry", and closing lines that restate what was just said. 4. Vary sentence length the way my sample does. Break up runs of three-item lists and paragraphs that all share the same shape. 5. Replace vague statements with a concrete example from the draft, or flag the spot with [EXAMPLE?] if the draft has none. 6. Keep the spelling conventions (US or UK) shown in my sample. </instructions> <constraints> - Do not add facts, opinions or stories that are not in the draft. - Do not add slang or jokes my sample does not use. - Keep the length within 10 percent of the draft. </constraints> <output_format> My voice: the five points. The rewritten draft. Changes: up to five bullets on the biggest edits and why they were made. </output_format>
Light edit only You are an editor who makes drafts sound like the person whose name is on them. <context> A sample of my own writing (300 words or more, written without AI): [MY SAMPLE] The draft to rewrite: [DRAFT] Where it will be published and who reads it: [PLACE AND READERS] </context> <instructions> 1. Study my sample first. Describe my voice in five short points: sentence length, word choice, how I open and close, how formal I am, and any habits such as questions, asides or humour. 2. Make the smallest changes that bring the draft into that voice. Keep its structure and as many of its sentences as possible, along with every fact, claim and link. 3. Cut stock phrasing that sounds machine-made: openers like "In today's fast-paced world", words like "delve", "leverage", "robust", "seamless" and "tapestry", and closing lines that restate what was just said. 4. Vary sentence length the way my sample does. Break up runs of three-item lists and paragraphs that all share the same shape. 5. Replace vague statements with a concrete example from the draft, or flag the spot with [EXAMPLE?] if the draft has none. 6. Keep the spelling conventions (US or UK) shown in my sample. </instructions> <constraints> - Do not add facts, opinions or stories that are not in the draft. - Do not add slang or jokes my sample does not use. - Keep the length within 10 percent of the draft. </constraints> <output_format> My voice: the five points. The rewritten draft. Changes: up to five bullets on the biggest edits and why they were made. </output_format>
If the result isn't right
- Pick a sample of the same type as the draft: an email for emails, an article for articles. Voice shifts between formats more than most people expect.
- Save the five-point voice description and paste it into future prompts as "write in this voice"; drafts start closer to you from then on.
- Read the result aloud. Any sentence you would never say to a colleague is still the model's, so rewrite that line by hand.