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 gebruder/wirken --skill calculatorgit clone --depth 1 https://github.com/gebruder/wirkenWrote 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/gebruder/wirken/calculator)<a href="https://agentmods.dev/skills/gebruder/wirken/calculator"><img src="https://agentmods.dev/badge/skills/gebruder/wirken/calculator/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/gebruder/wirken/calculator"><img src="https://agentmods.dev/badge/skills/gebruder/wirken/calculator.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 | $0.00007 | $0.00336 |
| Opus 5 | $0.00003 | $0.00168 |
| Sonnet 5 | $0.00001 | $0.00067 |
| Haiku 4.5 | $0.00001 | $0.00034 |
Grade A, and why
calculator 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.
What it actually says
Calculator
Perform calculations using shell tools.
Arithmetic
- Basic math:
echo "scale=4; 355/113" | bc -l - Percentages:
echo "scale=2; 847 * 0.15" | bc -l - Powers:
echo "2^32" | bc - Square root:
echo "scale=4; sqrt(2)" | bc -l
Python (if available)
For complex math: python3 -c "import math; print(math.log2(1024))"
Unit conversions
- Bytes to human:
numfmt --to=iec 1073741824(gives 1.0G) - Human to bytes:
numfmt --from=iec 4G(gives 4294967296) - Temperature:
python3 -c "c=37; print(f'{c}C = {c*9/5+32}F')"
Date math
- Days between dates:
echo $(( ($(date -d 2025-12-31 +%s) - $(date +%s)) / 86400 )) days - Date in N days:
date -d "+30 days" +%Y-%m-%d - Timestamp to date:
date -d @1700000000
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 · 40 lines · 7 tokens per session scan A e71d5e254da7
calculator is a skill published in the GitHub repository gebruder/wirken (171 stars, last pushed 5d ago), licensed MIT. It adds 7 tokens to every session and 336 once invoked, about $0.0000 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 2026-08-30.
Other skills, from other repositories
edgeone skill scanner
A local static scanner that checks agent-skill files for security risks before they are installed or used. Static analysis examines files without running them.
aig-scanner
A.I.G Scanner — AI security scanning for infrastructure, AI tools / skills, AI Agents, and LLM jailbreak evaluation via Tencent Zhuque Lab AI-Infra-Guard. Uses built-in exec + Python script, no plugin required. Requires AIGBASEURL to be configured. Triggers on: scan AI service, AI vulnerability scan, scan AI infra…
cocotrace
Build and query the SHA-256 requirements-to-implementation traceability graph across lifecycle artifacts.
cocoaudit
View and export the append-only session audit trail for regulated environments.
defenseclaw-ops
Manage DefenseClaw enterprise security - scan components, manage tool permissions, view alerts, configure guardrails.
squirrelscan
Skill "squirrelscan" from squirrelscan/squirrelscan, covering squirrelscan cli, links, install, command overview and quickstart.