Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add Ken-Technology/cold-email-skills --skill prompt-writergit clone --depth 1 https://github.com/Ken-Technology/cold-email-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/ken-technology/cold-email-skills/prompt-writer)<a href="https://agentmods.dev/skills/ken-technology/cold-email-skills/prompt-writer"><img src="https://agentmods.dev/badge/skills/ken-technology/cold-email-skills/prompt-writer/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/ken-technology/cold-email-skills/prompt-writer"><img src="https://agentmods.dev/badge/skills/ken-technology/cold-email-skills/prompt-writer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00063 | $0.04637 |
| Opus 5.5 | $0.00025 | $0.01855 |
| Sonnet 5.5 | $0.00013 | $0.00927 |
| Haiku 4.5 | $0.00006 | $0.00464 |
Grade A, and why
prompt-writer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 309 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Prompt Writer Skill
Write the AI personalization prompts (AI variables) for one campaign segment into the segment's prompts.md, with an optional rewriting steering paragraph, and test each prompt by hand on 3 to 5 sample prospects in any LLM. The user runs them per prospect in their own personalization tool (an AI column in Clay, their sending tool's AI step, or any LLM). You write only the user prompts (to_output: true) and the optional steering paragraph; the supporting context (who the sender is, the company context, the writing rules, the email sequence) comes from research.md and emails_v2.md when they run.
Never send or launch anything. Removing a variable from prompts.md happens only after the user asks for it.
Where this fits: after campaign-strategy, email-copywriting and email-review have set the AI variable names and placed their {{Title Case}} tokens in emails_v2.md; the last step before the segment is ready to send.
Inputs
{workspace} = the campaign workspace (default ./cold-email/{slug}/); {segment_folder} = the segment's folder in it (0 - default/, 1 - {segment-slug}/).
- Strategy AI variables (name, placement, short description): the AI variables section of
{segment_folder}/strategy.md, or from the caller. - The sequence:
{segment_folder}/emails_v2.md, the reviewed copy (emails.mdwhen there is no v2 yet). Every{{Title Case}}token in a subject or body needs a prompt. - Written prompts:
{segment_folder}/prompts.mdwhen it exists. - Company context: the
## Company Contextsection of{workspace}/research.md(its summary when there is none), plus the rest of the research and the client notes in{workspace}/notes.md. - Data sources: what the user's personalization tool gives the AI for each prospect (see Data Source Constraints).
The prompts live in {segment_folder}/prompts.md.
Live constraints (HARD)
Personalization tools enforce limits like these, and the copy relies on them. Breaking one fails the import or silently breaks the sequence.
What ships with it
3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 9d ago Changed · -203 lines · -8 tokens per session 45647478db33
- 2mo ago First seen · 512 lines · 71 tokens per session scan A 2edbf4c4ebf9
prompt-writer is a skill published in the GitHub repository Ken-Technology/cold-email-skills (4 stars, last pushed 6d ago), licensed MIT. It adds 63 tokens to every session and 4,637 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
prompt-writer compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| prompt-writerKen-Technology/cold-email-skills | Skill | 4 | 6d ago | MIT | A | 63 | Claude Code, Codex |
| llm-app-patternsdavila7/claude-code-templates | Skill | 33k | today | MIT | A | 54 | Claude Code, Codex |
| prompt-engineerJeffallan/claude-skills | Skill | 12k | 7d ago | MIT | A | 93 | Claude Code |
| prompt-optimizationlangwatch/langwatch | Skill | 5.0k | today | Apache-2.0 | A | 105 | Claude Code, Codex |
| ideogram4digitalsamba/claude-code-video-toolkit | Skill | 2.5k | today | MIT | A | 99 | Claude Code |
| prompt-library-for-startupsaws/agent-toolkit-for-aws | Skill | 3.4k | today | Apache-2.0 | A | 228 | Claude Code |
| hve-buildermicrosoft/hve-core | Skill | 1.6k | today | MIT | A | 54 | Claude Code |