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 posit-dev/skills --skill r-cran-extrachecksgit clone --depth 1 https://github.com/posit-dev/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/posit-dev/skills/r-cran-extrachecks)<a href="https://agentmods.dev/skills/posit-dev/skills/r-cran-extrachecks"><img src="https://agentmods.dev/badge/skills/posit-dev/skills/r-cran-extrachecks/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/posit-dev/skills/r-cran-extrachecks"><img src="https://agentmods.dev/badge/skills/posit-dev/skills/r-cran-extrachecks.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 | $0.00100 | $0.04079 |
| Opus 5.5 | $0.00040 | $0.01632 |
| Sonnet 5.5 | $0.00020 | $0.00816 |
| Haiku 4.5 | $0.00010 | $0.00408 |
Grade A, and why
r-cran-extrachecks 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 11d 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 — 485 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CRAN Extra Checks
Help R package developers prepare packages for CRAN submission by systematically checking for common ad-hoc requirements that CRAN reviewers enforce but devtools::check() doesn't catch.
Workflow
- Initial Assessment: Ask user if this is first submission or resubmission
- Run Standard Checklist: Work through each item systematically (see below)
- Identify Issues: As you review files, note specific problems
- Propose Fixes: Suggest specific changes for each issue found
- Implement Changes: Make edits only when user approves
- Verify: Confirm all changes are complete
Standard CRAN Preparation Checklist
Work through these items systematically:
- Create NEWS.md: Run
usethis::use_news_md()if not already present - Create cran-comments.md: Run
usethis::use_cran_comments()if not already present - Review README:
- Ensure it includes install instructions that will be valid when the package is accepted to CRAN (usually
install.packages("pkgname")). - Check that it does not contain relative links. This works on GitHub but will be flagged by CRAN. Use full URLs to package documentation or remove the links.
- Does the README clearly explain the package purpose and functionality?
- Important: If README.Rmd exists, edit ONLY README.Rmd (README.md will be overwritten), then run
devtools::build_readme()to re-render README.md
- Ensure it includes install instructions that will be valid when the package is accepted to CRAN (usually
- Proofread DESCRIPTION: Carefully review
Title:andDescription:fields (see detailed guidance below) - Check function documentation: Verify all exported functions have
@returnand@examples(see detailed guidance below). Note the exemption for S3 methods documented only with#' @export: they produce no.Rdfile and are not required to have either tag - Verify copyright holder: Check that
Authors@R:includes a copyright holder with role[cph] - Review bundled file licensing: Check licensing of any included third-party files
- Run URL checks: Use
urlchecker::url_check()and fix any issues
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.
- 11d ago Changed · +19 lines b036fd03f708
- 12d ago First seen · 466 lines · 100 tokens per session scan A f4e81356c1ab
r-cran-extrachecks is a skill published in the GitHub repository posit-dev/skills (543 stars, last pushed 3d ago), licensed MIT. It adds 100 tokens to every session and 4,079 once invoked, about $0.0004 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 2026-10-07.
Other skills, from other repositories
phx-deps-audit
Audit Hex deps for supply-chain security risk — bidi chars, compile-time exec, maintainer changes, typosquats, CVEs. Use after mix deps.update, when checking if a package upgrade is safe, or reviewing mix.lock PR diffs.
architect
Design the idiomatic Elixir architecture for a rewrite: set the compatibility bar (ADR-000), consult phx specialists on open questions, then build contexts, ledger and ADRs. Use after /rewrite:analyze.
deps-vet
Record a vetted Hex package version in hexvet.exs after a security review — manages the audit ledger, not the scanner. Use to approve a dep after /phx:deps-audit findings or to initialize hexvet.exs.
phx-plan
Plan features spanning multiple domains: billing (Stripe), auth (RBAC), real-time (Presence), webhooks, jobs (Oban). Use when designing interconnected systems or converting review findings into tasks.
deps-update
Bump outdated Hex deps — inventory, snapshot changelogs, update, fix breaks, split reviewable PRs (patches bundled, majors solo). Use to upgrade/bump Elixir dependencies or when versions fall behind. NOT for deps.get failures (/phx:investigate).
phx-deps-update
Bump outdated Hex deps — inventory, snapshot changelogs, update, fix breaks, split reviewable PRs (patches bundled, majors solo). Use to upgrade/bump Elixir dependencies or when versions fall behind. NOT for deps.get failures (phx-investigate).