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 elliotllliu/agent-shield --skill skillgit clone --depth 1 https://github.com/elliotllliu/agent-shieldWrote 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/elliotllliu/agent-shield/skill)<a href="https://agentmods.dev/skills/elliotllliu/agent-shield/skill"><img src="https://agentmods.dev/badge/skills/elliotllliu/agent-shield/skill/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/elliotllliu/agent-shield/skill"><img src="https://agentmods.dev/badge/skills/elliotllliu/agent-shield/skill.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 | $0.00092 | $0.00777 |
| Opus 5.5 | $0.00037 | $0.00311 |
| Sonnet 5.5 | $0.00018 | $0.00155 |
| Haiku 4.5 | $0.00009 | $0.00078 |
Grade A, and why
agent-shield 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 2mo 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 — 80 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AgentShield — Security Scanner
Scan any directory for security issues in AI agent skills, MCP servers, and plugins.
Usage
# Basic scan
npx @elliotllliu/agent-shield scan ./path/to/skill/
# Pre-install check (GitHub URL, npm package, or local path)
npx @elliotllliu/agent-shield install-check https://github.com/user/repo
# JSON output for programmatic use
npx @elliotllliu/agent-shield scan ./path/to/skill/ --json
# Fail if score is below threshold
npx @elliotllliu/agent-shield scan ./path/to/skill/ --fail-under 70
# Scan .difypkg plugin archives
npx @elliotllliu/agent-shield scan ./plugin.difypkg
What It Detects (30 rules)
High Risk:
data-exfil— reads sensitive files + sends HTTP requestsbackdoor— eval(), exec(), dynamic code executionreverse-shell— outbound socket to shellcrypto-mining— mining pool connectionscredential-hardcode— hardcoded API keys/tokensobfuscation— base64+eval, hex stringsprompt-injection— 55+ patterns, 12 categories, 8 languagestool-shadowing— tool name/description manipulationattack-chain— multi-step kill chain (5 stages)cross-file— cross-file data flow and code injectionast-*— Python AST taint tracking (eval, pickle, SQL injection, SSTI)multilang-injection— 8-language prompt injectiondescription-integrity— semantic mismatch between description and codemcp-runtime— MCP server runtime security issues
Medium Risk:
env-leak— process.env exfiltrationnetwork-ssrf— user-controlled URLs, SSRFprivilege— SKILL.md permission vs code mismatchsupply-chain— known CVEs in dependenciessensitive-read— SSH keys, AWS creds accessphone-home— periodic beacon/heartbeat patternpython-security— 35 Python-specific patterns
Low Risk:
excessive-perms— too many permissions declaredhidden-files— .env with secrets committedtyposquatting— suspicious npm package names
Interpreting Results
- Score 90-100: Low risk ✅
- Score 70-89: Moderate risk — review warnings
- Score 40-69: High risk — investigate before using
- Score 0-39: Critical risk — do not install
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.
- 2mo ago First seen · 80 lines · 92 tokens per session scan A a32d8b1a02ae
agent-shield is a skill published in the GitHub repository elliotllliu/agent-shield (16 stars, last pushed 7mo ago), licensed MIT. It adds 92 tokens to every session and 777 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 2026-08-30.
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