     @
     @#
    @%##
   @%%@=#
   @%%@==
  *%%%%#==
  @%%%%@===
 *%%%%%@====
 @%%%%%%#====
*%%%%%@@###===
@@@%%%++%::++##
 %++++++%:::::+
   ++++++::::+
    %+++++::+
      ++++::
       %+%:
         %

copy-editing

what it does

When the user wants to edit, review, or improve existing marketing copy, or refresh outdated content. Also use when the user mentions 'edit this copy,' 'review my copy,' 'copy feedback,' 'proofread,' 'polish this,' 'make this better,' 'copy sweep,' 'tighten this up,' 'this reads awkwardly,' 'clean up this text,' 'too wordy,' 'sharpen the messaging,' 'refresh this content,' 'update this page,' 'this content is outdated,' or 'content audit,' 'this sounds like AI,' 'AI slop,' 'de-slop this,' or 'make it sound human.' Use this when the user already has copy and wants it improved or refreshed rather than rewritten from scratch. Every edit removes AI tells such as 'it's not X, it's Y' reveals, 'no X, no Y, no Z' lists, and sentences that trail into extra comma clauses. A request to fix one line gets a point edit that changes only that line. For writing new copy, see copywriting.

by Corey Haines · Corey Haines, MIT · version 1 · license MIT

Verified Before and after: 2 models 1 try per case View source Download .zip

Compare the answers

Answers from Claude Sonnet 5.5 and GPT-6.1 Sol · try 1 of 1

Same request, same model, once with the skill and once without. Read both and judge for yourself.

“Run your AI-slop check on this landing page section before it ships. Only change what actually needs changing. Headline: Close the books in two days instead of ten. Subhead: Ledgerly matches bank transactions to invoices every night, keeping your existing account codes. CTA: Start a 14-day trial. No card required. Features: Bank matching, approval routing, and audit trails. FAQ: Does it work with NetSuite? Yes. It syncs both ways every hour.”

with the skill

**No changes needed. This section passes the AI-tell check.** - **Headline:** The claim is a concrete number with no contrast reveal, stock phrase, or em dash. - **Subhead:** The trailing clause ("keeping your existing account codes") adds a new fact rather than restating the claim, so it's not a pile-on. - **CTA:** "No card required" is a single risk reducer next to the CTA, which is fine. - **Features:** There are three, and they're real features, so the list of three is justified. - **FAQ:** The question is a reader's own, and the answer is direct with a specific detail (two-way, hourly). Rewriting any of it would be different, not better. **One flag, not changed:** "Two days instead of ten" is the strongest claim on the page and has no visible support. If you have a customer result or average from real accounts, put it near the headline (for example, "[NEED: customer name, their before/after close time]"). If it's a projection, soften the wording.

without

**Verdict: it passes. I wouldn't change any of the copy.** - **Headline:** Specific, with concrete numbers and an outcome. No filler verbs or vague promises. - **Subhead:** Says what the product does, when, and what it preserves. "Existing account codes" is a real detail a finance person cares about. - **CTA:** Trial length and the no-card condition are stated plainly. - **Features:** Plain nouns, no inflated adjectives. It's terse, but it isn't slop. - **FAQ:** Direct answer, with the sync direction and frequency included. **Things to check before shipping (not copy edits):** 1. **Is "two days instead of ten" defensible?** If it's a typical customer result, consider a source or qualifier nearby, such as "Customers average…" If it's an aspirational figure, soften it. This is a substantiation question, not a style one. 2. **Nightly matching vs. hourly NetSuite sync:** These are different processes, so it's not a contradiction. If someone might read them as one, a short clarification in the FAQ would help, but only if you've seen that confusion. Beyond that, I'd leave it alone.

Answers are shown exactly as the model wrote them, from the first try, and nothing is picked by hand.

The models

2 models

Claude Sonnet 5.5

made by Anthropic

claude-sonnet-5-5 · revision not reported by the provider

1 try per case · tested 1 Nov 2026

GPT-6.1 Sol

made by OpenAI

gpt-6.1-sol · revision not reported by the provider

1 try per case · tested 1 Nov 2026

The tasks

Our tests

headline-only

“Can you fix just the headline? The rest is fine.”

keep-founder-voice

“Clean this up a bit for our launch post.”

polish-hero

“Polish this homepage hero for us.”

refresh-faq

“This pricing FAQ is out of date. Our free plan now includes 3 projects instead of 1, and we dropped the discount that only applied to annual billing. Please update it.”

too-wordy

“This is too wordy. Tighten it up.”

The creator’s own tests

creator-1

“Edit this homepage copy for us: 'Welcome to CloudSync! We are very excited to offer you an innovative, cutting-edge platform that seamlessly integrates with your existing tools. Our powerful solution helps businesses of all sizes optimize their workflows and drive meaningful results. Get started today and experience the difference!'”

creator-2

“Quick edit on this CTA section: 'Ready to take your business to the next level? Our team of dedicated professionals is standing by to help you achieve your goals. Click here to learn more about how we can help you succeed.'”

creator-3

“edit this product description, it feels too long and wordy: 'Our comprehensive project management solution provides teams with a robust set of tools that enable them to efficiently plan, execute, and monitor their projects from start to finish. With our intuitive interface, powerful analytics dashboard, and seamless integration capabilities, you can ensure that every aspect of your project is managed with precision and care. Whether you're a small startup or a large enterprise, our platform scales to meet your unique needs and requirements, helping you deliver projects on time and within budget every single time.'”

creator-4

“Review this testimonial section and improve it: 'CloudSync is great! It really helped our company. The team was very responsive and the product works well. We would recommend it to anyone looking for a solution. - John S., CEO'”

creator-5

“I need you to apply the 'So What' and 'Zero Risk' sweeps to this pricing page copy: 'Our Pro plan includes unlimited projects, advanced reporting, priority support, and custom integrations. Starting at $99/month.'”

creator-6

“Write fresh homepage copy for our new product. We're launching a CRM for real estate agents.”

creator-7

“My client says this copy reads like AI slop. Fix it: 1. Most agencies have a folder of campaign ideas nobody will ever launch. Not because they're bad ideas. Because each one needs a developer. 2. No onboarding call, no spreadsheet templates, no chasing approvals by email. No contract. 3. Reports, alerts, and client dashboards all update straight from the ad accounts you already connected, no exports, no manual refresh, no second copy of the data to maintain.”

creator-8

creator-9

“Just fix the headline, it feels flat. Leave the rest alone. Headline: Better invoicing for small agencies Subhead: Ledgerly sends invoices the day a project milestone closes and chases late payers for you, so most clients pay within 9 days. Body: We built Ledgerly after our own agency waited 61 days on a $40k invoice. Connect Asana or ClickUp, pick which milestones bill, and Ledgerly drafts the invoice for you to approve. CTA: Start a 14-day trial”

Install

Download the .zip and unzip it. Put its files, in a folder named copy-editing, here:

Claude Code~/.claude/skills/Every project. For one project only, use .claude/skills/ inside it.

Codex~/.agents/skills/Every project. For one repository only, use .agents/skills/ inside it.

Cursor~/.cursor/skills/Cursor also reads the Claude Code and Codex folders above.

Then start a new session and ask for what the skill does. Other agents that read SKILL.md have their own skills folder; check their docs.

Coming after launch: get skills from inside your agent, no download needed.