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 Infrasity-Labs/dev-gtm-claude-skills --skill cover-lettergit clone --depth 1 https://github.com/Infrasity-Labs/dev-gtm-claude-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/infrasity-labs/dev-gtm-claude-skills/cover-letter)<a href="https://agentmods.dev/skills/infrasity-labs/dev-gtm-claude-skills/cover-letter"><img src="https://agentmods.dev/badge/skills/infrasity-labs/dev-gtm-claude-skills/cover-letter/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/infrasity-labs/dev-gtm-claude-skills/cover-letter"><img src="https://agentmods.dev/badge/skills/infrasity-labs/dev-gtm-claude-skills/cover-letter.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 | $0.00013 | $0.00714 |
| Opus 5 | $0.00006 | $0.00357 |
| Sonnet 5 | $0.00003 | $0.00143 |
| Haiku 4.5 | $0.00001 | $0.00071 |
Grade A, and why
cover-letter 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 — 101 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Cover Letter Skill
Priority hierarchy: See
references/priority-hierarchy.mdfor conflict resolution.
Write natural, persuasive cover letters that sound like a real professional wrote them.
File Structure
scripts/
write-cover-letter.md # Cover letter writing agent prompt
Data Directory
Resolve the data directory using references/data-directory.md.
Workflow
Step 0: Check Prerequisites
Resolve the data directory, then check prerequisites per references/prerequisites.md. Resume is required; profile is recommended but not blocking.
Step 1: Get Job Details
If $ARGUMENTS is "last" or empty:
- Check
DATA_DIR/jobs/for the most recently modified folder - If found, read
posting.mdandresume.mdfrom that folder - Confirm with the user which job this is for
- If no job folders exist, ask the user for a job URL
If $ARGUMENTS is a URL:
- Check if a job folder already exists for this company in
DATA_DIR/jobs/ - If yes, read the existing
posting.mdandresume.md - If no, use Claude in Chrome MCP tools to fetch the job posting per
references/browser-setup.md - Save the posting to
DATA_DIR/jobs/[company-slug]-[date]/posting.mdif not already saved
If the page can't be loaded, ask the user to paste the job description directly.
Step 2: Gather Materials
For the target job folder, check what exists:
posting.md- the job description (required)resume.md- a tailored resume (optional, improves quality significantly)
If no tailored resume exists, use the original resume and work history profile directly.
Step 3: Write the Cover Letter
Follow the framework in scripts/write-cover-letter.md. Use:
- The work history profile (or original resume if no profile)
- The tailored resume for this role (if available)
- The job posting
The cover letter must:
- Be 250-350 words
- Start with "Dear Hiring Manager,"
- End with "Regards, [Name]"
- Use ONLY hyphens, never em dashes
- Sound like a real human wrote it
- Never fabricate or exaggerate any detail
- Connect 2-3 specific, measurable achievements to the employer's needs
What ships with it
5 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 First seen · 101 lines · 13 tokens per session scan A accb3b3b04f2
cover-letter is a skill published in the GitHub repository Infrasity-Labs/dev-gtm-claude-skills (124 stars, last pushed 2mo ago), licensed MIT. It adds 13 tokens to every session and 714 once invoked, about $0.0001 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 2026-09-03.
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