qa-aman/ab-copy-writer

ab-copy-writer

Produces testable copy variants. Every variant has a distinct angle, a hypothesis for why it will outperform, and a predicted audience response. Stops marketers from shipping one version and guessing.

When to use

• "Write 3 variants of this LinkedIn post"
• "Give me A/B options for this email subject line"
• "Test different angles for our landing page hero"
• "I need to A/B test this ad headline"
• "Write copy variants for our webinar title"
• "Give me 5 versions of this CTA"

Inputs needed

1. The copy element: what needs variants (headline, subject line, hero, CTA, LinkedIn hook, ad copy, webinar title, email opener)
2. The source: existing copy to riff on, or a brief description of what it should accomplish
3. Number of variants: default is 3, max is 5
4. Channel: where this copy will run (LinkedIn, email, landing page, ad, webinar registration page)
5. What's being tested: angle, tone, format, CTA, or length (ask if not clear)

Angles this skill tests

For each variant, pick a distinct angle from this list. Never use the same angle twice in one set:

| Angle | Description | When it wins | |---|---|---| | Outcome-led | Leads with the specific result | When audience is ROI-focused and numbers-driven | | Pain-led | Opens on the problem, not the solution | When audience is in active pain and aware of it | | Speed-led | Emphasizes time-to-value | When audience is impatient or under pressure | | Contrarian | Challenges a common belief | When audience is saturated with standard messaging | | Social proof | Leads with a customer result or name | When audience trusts peers more than vendors | | Curiosity gap | Creates a knowledge gap that demands closing | When audience is information-hungry | | Specificity | Extremely specific number or detail as the hook | When vague claims are common and specifics stand out | | Fear of missing out | What happens if you don't act | When cost of inaction is high and under-communicated | | How-to | Practical, instructional framing | When audience wants actionable takeaways | | Founder/operator voice | Written as a practitioner to a practitioner | When audience distrusts brand voice |

Process

1. Load context. Read knowledge/brand/voice.md (for tone and style rules) and knowledge/icp/personas.md (for what this audience responds to). If either is missing, ask the user for the relevant context directly.

2. Check knowledge/learnings.md for any past A/B test results or copy performance data. If a previous test showed "outcome-led beats pain-led for our ICP", factor that in and note it.

3. Understand the goal. Ask if not provided: "What action should this copy drive? And what's the one thing the audience should feel or believe after reading it?"

4. Generate variants. For each:

   ## Variant [A/B/C/D/E]: [Angle name]
   
   **Copy:**
   [the actual copy - complete and ready to use]
   
   **Angle**: [name from the angles table]
   **Hypothesis**: [1-2 sentences on why this angle should outperform the others for this specific audience]
   **Predicted response**: [how the ICP is likely to feel reading this]
   **Best for**: [which segment of the ICP or which stage of the funnel this variant suits most]
   **Watch for**: [what signal would tell you this variant is winning - clicks, replies, saves, conversions]
   

5. Recommend the test setup:

   ## Recommended test setup
   
   **Test**: [Variant A] vs [Variant B] (start with the two most different angles)
   **Why these two**: [1 sentence on why this pairing gives the clearest signal]
   **Sample size needed**: [rough guidance - "at least 500 impressions per variant before reading results"]
   **How long to run**: [1-2 weeks for LinkedIn organic, 7 days minimum for paid, 3+ sends for email]
   **Primary metric**: [clicks / replies / saves / open rate / conversion - pick one]
   **How to read results**: [what delta counts as a win: ">10% difference in CTR is signal, <5% is noise"]
   

6. Self-check each variant:

   • Distinct angle from every other variant - no two variants are the same approach with different words
   • Matches knowledge/brand/voice.md style rules (no em dashes, no banned phrases, correct POV)
   • Uses language from knowledge/icp/personas.md where relevant
   • Hypothesis is specific to the ICP, not generic ("this will outperform because our ICP is measured on activation rate, not awareness, so outcome-led copy speaks directly to their KPI")

7. Save to output/ab-copy/<DD-MM-YYYY>-<copy-element-slug>.md with frontmatter:

   ---
   format: ab-copy
   element: [headline|subject-line|hero|cta|hook|ad]
   channel: [linkedin|email|landing-page|ad|webinar]
   variants: [number]
   angles: [list of angles used]
   created: DD-MM-YYYY
   ---
   

8. Offer follow-ups:

   • "Run /retro after the test and log which variant won and why. This gets appended to knowledge/learnings.md so future copy benefits from the result."
   • "Run /content-writer or /linkedin-post to build out the winning variant into a full piece."
   • "Want me to write the full ad set or email sequence using Variant [X] as the control?"

Copy length by channel

| Channel | Element | Length | |---|---|---| | LinkedIn | Hook (first 2 lines) | 15-25 words | | LinkedIn | Full post | 80-220 words | | Email | Subject line | 6-10 words | | Email | Preview text | 8-12 words | | Email | Opener (first sentence) | 10-20 words | | Landing page | H1 | 5-10 words | | Landing page | Sub-headline | 15-25 words | | Google ad | Headline | 30 chars max | | Google ad | Description | 90 chars max | | LinkedIn ad | Intro text | 150 chars max | | Webinar | Title | 8-12 words | | CTA button | Text | 2-5 words |

Rules

• Never produce variants that are only cosmetically different (swapping one word is not a different angle).
• Never use an angle that knowledge/learnings.md has already shown underperforms for this ICP without flagging: "Past data shows [angle] underperformed. Including it here for completeness, but Variant X is the higher-confidence bet."
• Every hypothesis must reference the ICP specifically. "This will perform well" is not a hypothesis. "Our ICP (Head of Growth, measured on activation rate) will respond to specificity because they are data-fluent and distrust vague ROI claims" is.
• Always recommend starting the test with the two most different variants, not adjacent ones. Adjacent variants give weak signal.
• If the user provides existing copy, always include one variant that is a direct evolution of their version (keep their angle, sharpen the execution) alongside genuinely different angles. They may want a baseline.