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 ur-grue/autopunk-media-skills --skill subject-line-writergit clone --depth 1 https://github.com/ur-grue/autopunk-media-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/ur-grue/autopunk-media-skills/subject-line-writer)<a href="https://agentmods.dev/skills/ur-grue/autopunk-media-skills/subject-line-writer"><img src="https://agentmods.dev/badge/skills/ur-grue/autopunk-media-skills/subject-line-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/ur-grue/autopunk-media-skills/subject-line-writer"><img src="https://agentmods.dev/badge/skills/ur-grue/autopunk-media-skills/subject-line-writer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00041 | $0.01115 |
| Opus 5 | $0.00020 | $0.00558 |
| Sonnet 5 | $0.00008 | $0.00223 |
| Haiku 4.5 | $0.00004 | $0.00112 |
Grade A, and why
subject-line-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 8d 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 — 79 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Subject Line Writer
What This Skill Does
Generates five distinct subject line options for a newsletter edition, each using a different psychological approach proven to improve open rates, matched to the publication's voice and the edition's content.
When To Use This Skill
- You have finished writing or briefing a newsletter edition and need to choose a subject line before sending
- Your open rates have plateaued and you want to test different subject line strategies
- You are launching a new newsletter and need to establish what subject line style fits your voice
- You are A/B testing subject lines and need a strong shortlist of candidates
What You Need To Provide
Required: A summary of the newsletter edition's main topic or story (2–5 sentences); the newsletter's name and general tone (e.g. "analytical and dry", "warm and conversational", "urgent and activist") Optional: Your typical subscriber profile; any subject lines that have performed well or badly for you before; the sending day and time; whether you allow emoji in subject lines
How the Assistant Approaches This
- Identifies the single most compelling element of the edition — the hook, the reveal, the tension, or the utility — that would make a reader stop scrolling
- Applies five distinct psychological frameworks: curiosity gap, direct value statement, personal relevance, urgency or scarcity, and contrarian or counterintuitive angle
- Calibrates each option to the newsletter's stated tone, keeping length under 50 characters where possible and avoiding spam-trigger language (all-caps, excessive punctuation, misleading claims)
- Adds a one-line note after each option explaining the psychological principle it uses, so you can make an informed choice or test intelligently
Output Format
Five numbered subject line options, each on its own line, followed by a parenthetical note explaining the technique. Total length: under 200 words. No preamble, no ranking. A single optional preview text suggestion (the 80–100 character line that appears after the subject in most clients) is appended at the end.
What ships with it
1 file 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.
- 8d ago First seen · 79 lines · 41 tokens per session scan A fe8f6bdfd008
subject-line-writer is a skill published in the GitHub repository ur-grue/autopunk-media-skills (32 stars, last pushed 12d ago), licensed MIT. It adds 41 tokens to every session and 1,115 once invoked, about $0.0002 per session on Opus 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 2026-09-04.
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