Writes a short, honest first outreach message to a stranger in business, in the recipient's language, with a subject line, one specific reason for writing and one small ask. Use when asked to write a cold email, a first outreach message, a sales or partnership introduction, or a prospecting note, in any language.

Cold Email is a SKILL.md that writes a short, honest first outreach message to a stranger in business, in the recipient's language, with a subject line, one specific reason for writing and one small ask; an agent buys it once for $0.03 over x402.

Tested 2026-09-30No code, no hidden instructionsv1.0.3 · 6.0 KB · perpetual license58 bought

Not for

Bulk or automated mass mailing, follow-up sequences, or inventing personal details about a recipient; it writes one honest first message from the facts you give it.

Tested, honestly

Tested 2026-09-30 with a strong and a weak model.

With and without the skill

Results with and without the skill, for Sonnet and Haiku
SonnetHaiku
withwithoutwithwithout
Cases passed6/60/66/61/6

One run per model and case. Mostly length: 57 to 102 words with the skill, 137 to 297 without it. Sonnet's content was as good without the skill; Haiku without it used one stock phrase and once addressed a Bulgarian reader informally.

Same cases and the same checks with and without the skill. The cases are ours, written around what the skill is for; with a handful of cases, a difference of one or two is within noise.

SonnetStrong model, claude-sonnet-5-5
6 of 6 cases pass (en, bg, de, es, ru, thin brief). Right language, formal address, 60-110 words, one ask, easy exit, and no invented facts: with almost no brief it wrote a role-based reason and said it was writing without prior contact.
HaikuWeak model, claude-haiku-4-5-20251001
6 of 6 pass the mechanical checks, but reading the texts shows real flaws: invents claims not in the brief ("most bakery owners I work with", "no massive minimums", "no surprise bills"), flatters ("great milestone"), ignores the formal-address rule in de/es/bg greetings (Hallo, Hola Laura, first-name only), leaves the Russian email without a greeting and with an English "Subject:" label, and on the thin brief does not say it is a first contact. Review its drafts before use.

Full test summary

Example

Our own test text, before and after the skill ran. Excerpts only.

English · claude-sonnet-5-5

Before

Sender: Mark Dolan, founder of Brightline Bookkeeping (small-business bookkeeping for cafes and bakeries, flat monthly fee). Recipient: Anna Reyes, owner of Corner Loaf Bakery. Real reason: Anna's bakery opened a second location this spring, per its own website. Language: English.

After

Subject: Bookkeeping for two locations Hi Anna, I saw on Corner Loaf's website that you opened a second location this spring, which is why I'm writing to you. I'm Mark Dolan, founder of Brightline Bookkeeping. We do bookkeeping for cafes and bakeries for a flat monthly fee. We have had no contact before, so this is a cold note.…

Bulgarian · claude-sonnet-5-5

Before

Подател: Иван Петров, управител на "ТехноСервиз" ЕООД (поддръжка на офис принтери, фиксирана месечна цена). Получател: Мария Георгиева, офис мениджър на счетоводна кантора "Баланс". Реална причина: кантората е с два етажа и повече от 20 служители, по данни от сайта ѝ. Език: български.

After

Тема: Поддръжка на принтери за кантората Здравейте, Мария Георгиева, пиша Ви като на офис мениджър на кантора, която според сайта Ви е на два етажа и с над 20 служители. Пиша Ви без предишен контакт. Казвам се Иван Петров и съм управител на "ТехноСервиз" ЕООД. Поддържаме офис принтери срещу фиксирана месечна цена. Ще Ви бъде ли полезно да Ви опиша в три реда как работи?…

German · claude-sonnet-5-5

Before

Absender: Lena Vogt, Inhaberin von Vogt Steuerdigital (Software zur Belegerfassung für Handwerksbetriebe). Empfänger: Herr Thomas Kraus, Geschäftsführer der Kraus Elektrotechnik GmbH. Echter Anlass: Die Firma sucht laut Website einen Bürokaufmann. Sprache: Deutsch.

After

Betreff: Belegerfassung für Ihr Büro Sehr geehrter Herr Kraus, auf Ihrer Website habe ich gelesen, dass die Kraus Elektrotechnik GmbH einen Bürokaufmann sucht. Deshalb schreibe ich Ihnen, ohne dass wir uns kennen. Ich bin Lena Vogt, Inhaberin von Vogt Steuerdigital, und wir bieten Software zur Belegerfassung für Handwerksbetriebe an.…

Spanish · claude-sonnet-5-5

Before

Remitente: Carlos Ibáñez, fundador de Ruta Verde Logística (reparto de última milla en bicicleta eléctrica). Destinatario: la señora Laura Méndez, directora de una tienda online de cosmética natural, Flor de Sal. Motivo real: Flor de Sal anuncia envío en 24 horas en su web. Idioma: español.

After

Asunto: Sobre su envío en 24 horas Estimada señora Méndez: Le escribo porque en la web de Flor de Sal anuncian envío en 24 horas, un plazo que depende mucho del reparto de última milla. Soy Carlos Ibáñez, fundador de Ruta Verde Logística, un servicio de reparto de última milla en bicicleta eléctrica. Le escribo sin contacto previo.…

Russian · claude-sonnet-5-5

Before

Отправитель: Сергей Волков, основатель студии Северный Двор (фотосъёмка товаров для интернет-магазинов, пакет на 50 фото). Получатель: Ольга Николаева, руководитель интернет-магазина детской одежды Мелкий. Реальный повод: в магазине на сайте у большинства товаров одна фотография. Язык: русский.

After

Тема: Фотографии товаров на сайте Здравствуйте, Ольга. Мы не знакомы, и пишу я потому, что на сайте магазина «Мелкий» у большинства товаров только одна фотография. Меня зовут Сергей Волков, я основатель студии «Северный Двор»: мы снимаем товары для интернет-магазинов. Есть пакет на 50 фото. Будет ли Вам полезно, если я в трёх строках опишу, как он устроен?…

What is in the file

  • Hard rules
  • Shape of the message
  • Subject line
  • Words to avoid
  • Format
  • When the brief is thin
  • Check before you answer

Languages

Any language. Tried in: English, Bulgarian, German, Spanish, Russian.

License

Perpetual, non-exclusive; use and modify for yourself incl. paid work; no resale or republishing. Holder: Georgi Kalchev, aiskills402.com. Full terms.

Versions

Current version 1.0.3, updated 2026-10-07. Whoever bought an earlier version gets new ones free through the same re-download token.

  1. v1.0.3 · 2026-10-07

    - Test summary: the length range with the skill was misstated as 76 to 102 words; counted again, it is 57 to 102 (the shortest is Haiku's Russian email). The skill file itself is unchanged.

  2. v1.0.2 · 2026-10-04

    - Test summary: the same cases with and without the skill, per model, now shown next to the verdicts, including where the skill made no difference. The skill file itself is unchanged.

  3. v1.0.1 · 2026-10-03

    - Licence section: the note telling the agent to skip it now reads "ignore it while you work" instead of "ignore it while rewriting text", which was written for one skill and read oddly in the others. The skill's own instructions are unchanged.

  4. v1.0.0 · 2026-09-30

    First release: a short, honest first outreach message with subject line, in the recipient's language.

FAQ

What does one email look like?

A subject line, a short body of roughly 60 to 110 words in the recipient's language, one specific reason for writing and a single small ask, with an easy way to say no. It does not stack several requests into one message.

What happens when I give it almost no information?

It does not make up a story. On a nearly empty brief, the strong model wrote a role-based reason for the contact and stated openly that it was writing without prior contact. Give it real facts about the recipient and your offer for a sharper message.

Is the small model good enough for this?

Read every draft. Claude Haiku passed our mechanical checks but added claims that were not in the brief, such as what most customers say, flattered the recipient and skipped the formal form of address in German, Spanish and Bulgarian. Claude Sonnet did none of that.

Read more

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Read this page as Markdown: /skills/cold-email.md.

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