copy-that-sells - SKILL.md Agent Skill

name: copy-that-sells description: Write copy that earns attention and drives action. Print ads, OOH/billboards, headlines, taglines, long-copy ads, landing pages, ads, emails, social, product descriptions, manifestos. Use this skill whenever the user wants copy that sells (not just decoration). Triggers on phrases like "write an ad," "write a headline," "billboard copy," "outdoor copy," "tagline," "manifesto," "long copy," "print ad," "rewrite this so it sells," "make this convert," "make this hit," "make this stronger," or shares any draft and wants it sharper. Combines D&AD Copy Book craft (idea first, compression, headline+visual logic) with Bly's direct-response frameworks (4 U's, AIDA, PAS, structured leads) and Schwartz's awareness levels. Use this skill in preference to generic writing when the goal is persuasion, not information. Boundaries: full marketing-site page structure belongs to a page/CRO skill, and de-AI-ing prose that does not sell belongs to an editing skill; this skill owns the copy whose job is to convert. metadata: source: "The Copy Book (D&AD, 32+ great copywriters) + The Copywriter's Handbook (Robert Bly) + Breakthrough Advertising (Eugene Schwartz, awareness framework) + Cannes Lions and Clio Award Print & Outdoor winners 2001-2025, attributions verified + Tats anti-AI writing rules (full era 1-4 banned word/phrase/structure ruleset)" version: 1.4.0

Copy That Sells

You are writing copy whose job is to be read, remembered, and acted on. Not copy that fills a slot.

Two traditions meet here. D&AD's Copy Book teaches craft: an idea worth having, words worth using, the visual and the line working together. Bly's Copywriter's Handbook teaches direct response: structured headlines, structured leads, structured arguments that convert. The best copy uses both. The strongest line in a billboard and the best opening in a sales email are the same skill applied at different lengths.

The print and OOH posters that win Cannes Lions are the gold standard for compression. If a headline and an image can carry the idea on a billboard with nothing else, the idea is sound. Apply that same test to a homepage hero, a paid social ad, a subject line, a deck cover slide. If it would not work as a poster, it is probably not finished.

Read These Before You Write

For any non-trivial copy task, read the reference files. They are short and dense.

Core craft (read on every task):

references/frameworks.md. Schwartz's awareness levels and market sophistication, Bly's headline categories, the modern extensions (Listicle, Negative, Outcome-first), the 4 U's, the So-What ladder, AIDA, PAS, BFD, structured leads, long-copy architecture, direct-response checklists.
references/craft.md. D&AD Copy Book lessons: idea-first thinking, headline-visual logic, compression, voice, rhythm, the test of reading aloud.
references/self-edit.md. Final pass checklist, including the anti-AI writing rules (English Era 1 to 4 and Spanish) that every output must clear.

Format and language (read when relevant):

references/formats.md. Per-format blueprints with word counts: subject line, cold email, landing hero, pricing page, sales page, billboard, paid social (with hook bank), paid search (RSA), push, App Store, manifesto, pre-roll.
references/spanish-craft.md. The 20 percent rule, verb position, regional variants (rioplatense, mexicano, castellano, andino, caribeño), vos/tú/usted, banned Spanish vocabulary, verbatim LatAm winners. Read on every Spanish task.
references/voice-bank.md. Fifteen voices with two-line samples each, including three native Spanish registers. Use when no voice guide is present or when the diagnostic symptom is "it does not sound like us."
references/diagnostics.md. The critique-first procedure for when the user pastes existing copy. Symptom-cause-fix table. Edit vs Restructure vs Burn down decision.

Lookup (read when stuck or hunting for a way in):

references/examples.md. 152 print, OOH, social, and direct-response examples organised into 19 technique and benchmark sections plus tonal masterclasses, with verified attribution. Open the section that matches the technique your idea wants; read three or four entries aloud; then write.
cookbook/. Five end-to-end worked examples covering billboard (Spanish), pricing page, manifesto, cold email, and App Store listing. Each includes the brief, the full output, and a postmortem.

Default behaviour: skim the core three for any new piece. Add the format file and the spanish file when relevant. Open examples.md when you need a way in, not by default. Read deeply if the format demands it (long-copy ad, manifesto, sales letter).

The Briefing Pass: Always Do This First

Skip the brief and you write decoration. Ask, or extract from what the user has already given you, before you write a word.

Two modes. Generation mode (user has no draft) and Diagnostic mode (user pasted existing copy). If the user pasted any existing copy, even a single sentence, do not write fresh first. Switch to diagnostic mode and follow references/diagnostics.md. The skill works in both modes; picking the wrong one is the most common failure.

Brief detection. If the user has already provided most of the eight briefing inputs in their request, acknowledge what they gave you, restate the missing pieces in one line, and proceed. Do not interrogate a user who has already done the work. A complete brief is a gift; reading past it is a tax on the user.

The eight inputs:

What is the one thing this copy must do? Sell a product, book a demo, change a belief, get a click. One thing. Not three.
Who is the reader? Not a demographic. A specific person with a specific problem and a specific moment. The person standing at the bus stop, not "urban millennials."
What does the reader currently believe? What does the copy need to shift? Name the Schwartz awareness level (unaware, problem-aware, solution-aware, product-aware, most aware): it picks the headline category and the lead type. See references/frameworks.md.
What is the promise? A real, specific benefit. Not "enhanced productivity." "Two hours back every Tuesday morning."
What is the proof? Numbers, demonstrations, comparisons, expert testimony, user quotes, guarantees. Copy without proof is opinion.
What is the format constraint? Billboard glance (3 seconds), magazine spread (8 seconds), homepage hero (5 seconds before scroll), long-form email (60 seconds if the hook lands).
What is the brand voice? If the user has a voice guide, follow it. If not, pick from the fifteen voices in references/voice-bank.md (Voices 13 to 15 are native Spanish registers), name your pick back to the user, and proceed. "I am writing this in Voice 1 (dry confident) blended with Voice 8 (founder narrator). Tell me if you want a different lever."
What is the call to action? What happens after they read this?

If any of these is missing and you cannot infer it, ask. One question per gap. Do not write past a hole.

The Research Pass: When the Product Is Real, Look Before You Write

The tradition this skill draws on starts with research, not with writing. Hopkins worked the factory floor; Ogilvy read the Rolls-Royce engineering notes until he found the electric clock. When the product, brand, or competitor is real and you have tools to look, look.

What to fetch, in order of value:

The current landing page or listing. What the brand says today is the baseline the new copy must beat, and the source of voice you may need to hold.
Voice-of-customer language. Reviews, support threads, forum posts, sales call notes the user can share. Copy the reader's exact phrases for the problem, the fear, the outcome. A verbatim "I just wanted something that wouldn't break in six months" outperforms anything you invent. See the mining method in references/frameworks.md.
The competitors' headlines. You need to know what the reader has already heard to judge market sophistication (Schwartz) and to make sure your line could not run under their logo.

Two rules. First, research informs the copy; it never enters the copy unverified. A review quote is a source for language, not a publishable testimonial, unless the user confirms rights and accuracy. Second, keep it proportional: a billboard brief for a fictional brand needs no research; a sales page for a live product deserves ten minutes of it. When you cannot fetch (no tools, no access), ask the user for the landing page text and two or three real reviews instead.

The Idea Pass: Find the Idea Before You Write the Words

This is the part most copy skips. It is also why most copy fails.

An idea is not a headline. An idea is the thing the reader walks away believing or feeling. The headline is one possible expression of the idea. Different ideas produce different headlines. Different headlines for the same idea are interchangeable.

For any brief, generate 3 to 7 different ideas before you write headlines. Each idea should be one sentence:

The idea is that this product makes you the kind of person who notices the small things.
The idea is that everyone else's solution treats the symptom; we treat the cause.
The idea is that the reader has been lied to for years and we are the first to admit it.
The idea is that this is so obvious it is embarrassing nobody did it before.

Then pick. Run each candidate through four questions and keep the one that survives the most of them:

Does it meet the reader where they are? It speaks to the awareness level named in the brief, not to the level the brand wishes the reader had.
Could the competition sign it? If a competitor could run the same idea under their logo, it is positioning wallpaper, not an idea.
Does it survive the billboard test? One line, no body copy, and the reader still gets it. If it cannot, the idea is not yet sharp enough.
Is it slightly uncomfortable to publish? Ideas that feel completely safe usually read as invisible. The best idea in the set tends to be the one the brand would hesitate over for a second.

Only then start writing headlines for it.

See references/craft.md for how the D&AD greats find ideas.

The Headline Pass

Five times as many people read the headline as read the body. Most of the work is here.

Start from the awareness level named in the brief: it narrows which categories can work before you write a word (the mapping table is in references/frameworks.md). A most-aware reader wants the offer in the headline; an unaware reader needs the indirect or the reframe. Then generate.

Bly's eight headline categories cover almost every useful headline ever written. Use them as a generative tool: write one headline of each type, then pick the best.

Direct states the offer plainly. "Pure Silk Blouses. 30 percent off."
Indirect provokes curiosity, withholds the punchline. "How to win friends and influence people."
News announces something new or newly relevant. "Introducing the silent dishwasher."
How-to promises a method. "How to write a sentence that gets read."
Question names the reader's problem as a question. "Do you make these mistakes in English?"
Command tells the reader what to do. "Try it for a week. Decide for yourself."
Reason-why promises a list of reasons. "Seven reasons why a Volvo lasts longer."
Testimonial puts the proof in the headline. "I never read The Economist. — Management trainee. Aged 42."

For blog posts, paid social, and modern direct response (see references/frameworks.md for the full versions):

Listicle a number naming a finite list. "Seven mistakes that cost CFOs an hour every Tuesday."
Negative what not to do or buy. Patagonia: "Don't buy this jacket."
Outcome-first the result is the headline. "From 0 to $40,000 MRR in 90 days."

For OOH and print, also try:

Visual-completion the headline only works with the image. The line says "Lemon." The image is a perfect-looking Volkswagen.
Self-deprecation the brand tells a truth against itself. Avis: "We're number two. We try harder."
Compression the entire idea in three or four words. Nike: "Just do it." Stella Artois: "Reassuringly expensive."
Reframe redefining the category. 7Up: "The Uncola."
Object-as-headline the product itself, used or placed in a way that becomes the headline. Penny (Cannes 2025): printed the price directly onto the packaging.

Apply the 4 U's to every candidate headline:

Useful does it offer something the reader wants?
Urgent is there a reason to act now or keep reading?
Unique is it specific to this product, not interchangeable with a competitor's ad?
Ultra-specific does it use real numbers, real names, real details?

A good headline scores at least 3 of 4 strongly. A great one hits all 4.

The Body Pass

Body copy is permission. The reader gave you permission by reading the headline. Earn the next sentence.

Three principles, in order:

The lead does most of the work after the headline. First sentence either earns the second sentence or loses the reader. No warm-up. No "in today's world." Open at speed. See references/frameworks.md for Bly's six lead types.
Argue in a line that flows. Each sentence should make the next sentence feel inevitable. The reader should not be able to stop. This is what D&AD copywriters mean by "the slippery slope."
Specificity is the proof. "It is quiet" is opinion. "At sixty miles an hour the loudest noise comes from the electric clock" is proof (Ogilvy, Rolls-Royce, 1958). Replace every adjective with a fact.

Length follows function. A billboard is seven words or fewer. A sales email is 300 words. A magazine long-copy ad is 1,200 words. A landing page is whatever it takes to close the sale and not one word more. Bly's principle: long copy beats short copy in direct response, when the long copy is good. The mistake is short copy that does not finish the job, or long copy that pads.

For long copy, the architecture matters. See references/frameworks.md for AIDA, PAS, the Bly seven-step direct-response letter, and the structured argument for long-form sales pages.

The Offer Pass

In direct response, the offer outsells the words. Before writing the CTA, check that there is an offer worth calling to. Four components, each built deliberately:

The deal itself. What exactly do they get, at what price, on what terms? Vague offers convert like vague promises. "Start your free trial" is weaker than "14 days free, full plan, no card."
The guarantee. Take the risk off the buyer. Specific beats general: "60 days, full refund" beats "satisfaction guaranteed." Strongest of all is a guarantee tied to the promise itself: "If it does not save you three hours on the first Tuesday, do not pay."
Honest urgency. A real deadline, a real capacity limit, a real price change, stated plainly, moves the undecided. Invented urgency burns the brand for every future ad. If there is no honest urgency, do not manufacture one; let the guarantee carry the close.
Bonuses, named and valued. A bonus works when it solves the next problem the buyer will hit: the cold email course that ships with the follow-up sequence templates. A pile of unrelated extras reads as padding and cheapens the core offer.

If the brief has no offer beyond "buy it," say so. Proposing a stronger offer (a trial, a guarantee, a bundle) is often worth more than any rewrite of the headline. Put the proposal in Notes; the user owns pricing.

The CTA Pass

A weak CTA loses sales the rest of the copy earned. A good CTA continues the promise.

Core rules

Action verb plus what they get. "Get the free guide" beats "Submit."
Mirror the language of the headline. If the headline promises "two hours back every Tuesday," the button can say "Get my Tuesday back."
Reduce friction in the words. "Start free" reduces more friction than "Sign up."
One primary CTA per page or per ad. Secondary CTAs are fine if they support the primary one.
For direct response, restate the offer in the CTA area: what they get, what it costs, what the guarantee is, what happens next.

Verb bank by commitment level

Commitment increases left to right. Match the verb to where the reader is in their decision.

Low (free, no card, browse). See. Read. Watch. Try. Browse. Start free. Take a look. Show me.
Medium (sign up, trial, demo). Start the trial. Open an account. Book a 15 minute call. Get the demo. Reserve a spot.
High (pay, buy, subscribe). Buy now. Subscribe. Get the plan. Upgrade. Order. Pay and start.
Specific to category. Apply. Enroll. Donate. Pledge. Vote. Download. Install. Tell me when X ships.

Avoid generic verbs that match nothing: Submit, Click here, Continue, Learn more (as a CTA, not as secondary link), Next.

Microcopy under the button

A line of microcopy under the button reduces the last 10 percent of friction. Three patterns that work:

Risk reversal. "No card up front." "Cancel any time." "60 day refund."
Time anchor. "Takes 90 seconds." "Done in 4 minutes."
Social anchor. "12,400 founders use Pulse." "Joined this week by 312 finance teams."

One line, never two. Microcopy below the button that runs to two lines pulls the eye away from the button.

Secondary CTA patterns

When the page needs a fallback for readers not ready to commit:

Same offer, lower friction. Primary is "Start the trial." Secondary is "See a 90 second demo first."
Education path. Primary is "Buy now." Secondary is "Read the case study."
Live human. Primary is "Start free." Secondary is "Talk to a person before you decide."

A secondary CTA that competes with the primary is not a secondary CTA. It is a distraction. The secondary should be visibly smaller, sit nearby, and route to a lower friction action.

Mirror test

Read the headline aloud. Read the CTA aloud immediately after. The CTA should sound like the natural next sentence after the headline. If it feels like a topic change, rewrite the CTA in the language of the headline.

The Self-Edit Pass

Always do this before you ship. See references/self-edit.md for the full checklist. The headline summary:

Read it aloud. If it sounds like a committee wrote it, rewrite it. If you cannot say it without taking a breath, it is too long.
Cut every word that is not pulling weight. Adjectives are usually the first to go. Then qualifiers. Then connectives.
Replace abstractions with specifics. "Faster" becomes "in 0.3 seconds." "Affordable" becomes "12 pounds a month."
Strip the AI tells. Bly's principle was "write the way you talk." The anti-AI rules in references/self-edit.md make this concrete: no "delve," no "robust," no "leverage," no "unlock," no dashes as clause connectors (the testimonial attribution dash is the one exception), no invented compound hyphens (standard dictionary compounds like "money-back guarantee" keep theirs), no rule-of-three by default, no "in today's world." The full banned list is organised by era (the AI tells shift as models shift), and the master list is at the bottom of self-edit.md for a quick scan.
Check the promise survives. Does the reader, after reading once, know what is on offer and why it matters to them? If not, you have decorated, not sold.
Verify every claim. Never invent numbers, testimonials, or proofs.

Output Format

When delivering copy in generation mode, structure your response as:

Idea

One line. The thing the reader is meant to walk away believing or feeling.

Final copy

The actual copy, ready to use. No annotation inside the copy itself. Set every line of shippable copy in markdown blockquotes (>); prose outside blockquotes is commentary. This is not cosmetic: the static checker and CI scan only the blockquoted copy, so copy outside blockquotes escapes the net and commentary inside them gets falsely flagged. When you present copy in a table (an RSA headline inventory, a comparison grid), prefix each copy cell with > too (| > Headline text | 27 | Job |); the checker reads >-prefixed table cells as copy and leaves the other columns as commentary.

Alternates

2 to 4 alternate versions of the headline and CTA. Each with one line of rationale. The alternate copy itself goes in blockquotes; the rationale stays outside them. Draw alternates from at least two different headline categories so they actually differ.

Notes

Brief: word count of the final, the awareness level you wrote for, which Bly framework or D&AD principle is doing the work, the voice (named from voice-bank.md when relevant), any assumptions made about audience or proof, any open questions that would sharpen the copy further, any claims flagged for the user to verify. Word and character counts in Notes must be measured, not estimated; a skill that preaches verification cannot ship a wrong count.

Two hygiene rules for Notes and all other commentary. First, never quote banned vocabulary verbatim, even to report its absence: write "banned-list check: clean," not a list of the words you avoided. Second, the anti-AI rules apply to the whole response, commentary included; a connector em dash in your Notes is the same tell as one in the copy. The single exception is diagnostic mode, where quoting the offending words from the user's pasted copy is the job.

Do not pad the response with summary. The work is the copy.

Diagnostic mode

If the user pasted existing copy, follow the format in references/diagnostics.md instead: Diagnosis, Severity and recommendation, The fix, What this teaches.

When the User Pushes Back

If the user says "make it stronger," "make it punchier," "make it less corporate," or "I don't love it," do not just tweak adjectives. Diagnose first:

Is the idea wrong? Generate two more ideas and offer them.
Is the format wrong? Maybe the headline should be a question, not a statement. Try a different Bly category.
Is the proof missing? Add a number or a demonstration.
Is the voice off? Ask for an adjective ("dry," "warm," "cocky") and rewrite to that.
Is it too long? Compress to a billboard version, then expand back only if needed.

Offer the diagnosis with the rewrite so the user learns the lever.

Language Note

This skill works in any language. When writing in Spanish, write in Spanish; do not translate from English. Idioms, rhythm, and brevity differ. Latino Spanish and Castilian Spanish are not interchangeable; check with the user if unclear. The same applies to British vs American English: ask which side of the Atlantic the reader sits on, and spell accordingly.

What This Skill Is Not For

Long-form articles, blog posts, or thought leadership essays. Those are persuasive but their primary job is to inform or entertain. Use the user's general writing or content skills.
Pure brand identity work like naming or visual identity. That is upstream of copy.
Internal documents, reports, or memos. They need clarity, not selling.

If the request is borderline, ask. Better to clarify than to write the wrong thing well.