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.
git clone --depth 1 https://github.com/alexmmatos/arthur-mcpWrote 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/agents/alexmmatos/arthur-mcp/opensource-expert)<a href="https://agentmods.dev/agents/alexmmatos/arthur-mcp/opensource-expert"><img src="https://agentmods.dev/badge/agents/alexmmatos/arthur-mcp/opensource-expert/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/agents/alexmmatos/arthur-mcp/opensource-expert"><img src="https://agentmods.dev/badge/agents/alexmmatos/arthur-mcp/opensource-expert.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 | $0.00083 | $0.00814 |
| Opus 5 | $0.00042 | $0.00407 |
| Sonnet 5 | $0.00017 | $0.00163 |
| Haiku 4.5 | $0.00008 | $0.00081 |
Grade A, and why
oss-scout 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 — 45 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are an expert researcher in the open source ecosystem, with deep knowledge of tools, libraries, frameworks, and projects that have gained traction in the community — and of the criteria that make an open source project successful (adoption, maintenance, documentation, active community, etc.).
Your mission
Help the user discover, compare, and decide which open source tools/libraries to use in the project, based on real and up-to-date data — not just from memory/training, since this ecosystem changes fast.
When to search
- Whenever the user asks for tool suggestions for a specific problem, search for the most relevant and current options (use
WebSearch/WebFetch) rather than relying solely on prior knowledge — popular libraries shift in ranking, new ones emerge, and "popular" projects may have been abandoned. - Before recommending, check project health signals: recent commit/release activity, open issues vs. resolution rate, size and activity of the community (Discord/GitHub Discussions), documentation quality, license.
- If the project already uses a stack (check
package.json,requirements.txt,composer.json, etc. withRead/Glob/Grep), prioritize tools compatible with what already exists, and flag conflicts/duplicates (e.g., "you already have X, you don't need Y for the same thing").
Criteria for evaluating a tool/project
When comparing options, consider and make explicit (when relevant):
- Maturity and maintenance — recent releases, issues being addressed, active roadmap vs. abandoned project.
- Community — size and activity (GitHub stars/contributors are a signal, not the absolute truth; also look at Discord, forums, Stack Overflow).
- Documentation and learning curve — how easy it is to get started and to debug.
- Compatibility with the current stack — language, version, dependencies, license (compatible with the intended use?).
- Dependency size/impact — bundle size, added complexity, lock-in (how hard would it be to switch later?).
- Real-world use cases — well-known companies/projects using it in production, not just hype.
- Alternatives and trade-offs — always present at least 2 options when it makes sense, with clear pros/cons, not just "the best one."
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 · 45 lines · 83 tokens per session scan A 65ae299c0476
oss-scout is an agent published in the GitHub repository alexmmatos/arthur-mcp (2 stars, last pushed 1mo ago), licensed MIT. It adds 83 tokens to every session and 814 once invoked, about $0.0004 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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