email-copywriting

How to write copy

Output Contract

emails_v2.md (and emails.md) must follow a fixed structure so downstream campaign tooling can parse them reliably. Hard rules this skill must honor:

• ## Email N: {Descriptive Title} - the title is the sequence step name (truncated to 25 chars). Missing title → step name falls back to Variant A.
• ### Variant A (desc) / ### Variant B (desc) - literal word Variant, never Version (tools should warn on Version). Letter in A..D. Parenthetical description becomes the step-name suffix.
• Combined step name {title} - {variant_desc} must be ≤25 chars. Longer strings get truncated - authors should pre-shorten to preserve intent.
• AI variables use double braces {{Title Case}} (uppercase-first required): {{First Line}}, {{PS Line}}, {{Subject Line}}. This is the canonical form for personalization tools and LLMs. (Legacy [Title Case] square brackets are still often auto-converted, but write {{...}} in all new copy.)
• Lead variables use {camelCase}: {firstName}, {company}. Never {first_name}.
• Signatures use the system variable {sender_signature} (single braces) in place of any hand-written sign-off - on every email. See the Signature rule below.
• Never write {{tracking_link:...}} in local copy - write raw URLs or markdown links; tracking wrappers are tool-side if used.
• End the file with a terminator H2 (## Notes, ## Signature Block, ## AI Personalization Placeholders) so trailing metadata doesn't get swallowed into the last email's body. Also supported: **Variant Notes**: / **Test Notes**: inline markers.
• Every AI variable used (e.g. {{First Line}}) must have a matching H3 in prompts.md. {{Subject Line}} is the exception you don't have to write: many personalization stacks auto-emit a Subject Line output prompt for it (kept to_rewrite=0, so it's generated but never rewritten). Add a ### Subject Line H3 only when you want to override the default.

Overview

This skill provides comprehensive guidance for writing effective cold email copy. Use this skill when creating email sequences, writing cold outreach, or reviewing email campaigns. Claude should reference these guidelines whenever writing or reviewing cold email copy.