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 monte-carlo-data/mc-agent-toolkit --skill preventgit clone --depth 1 https://github.com/monte-carlo-data/mc-agent-toolkitWrote 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/monte-carlo-data/mc-agent-toolkit/prevent)<a href="https://agentmods.dev/skills/monte-carlo-data/mc-agent-toolkit/prevent"><img src="https://agentmods.dev/badge/skills/monte-carlo-data/mc-agent-toolkit/prevent/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/monte-carlo-data/mc-agent-toolkit/prevent"><img src="https://agentmods.dev/badge/skills/monte-carlo-data/mc-agent-toolkit/prevent.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to high
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- high Prompt Injection · line 276 Hidden instructions were detected in comments or invisible text. These could contain malicious directives. Manual review is recommended.Fix: Audit all comments and invisible characters. Remove any instructions that direct the agent to perform unauthorized actions. Use plain, reviewable content.
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 | $0.00052 | $0.04243 |
| Opus 5.5 | $0.00021 | $0.01697 |
| Sonnet 5.5 | $0.00010 | $0.00849 |
| Haiku 4.5 | $0.00005 | $0.00424 |
Grade A, and why
monte-carlo-prevent 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 1mo 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 — 325 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Monte Carlo Prevent Skill
This skill brings Monte Carlo's data observability context directly into your editor. When you're modifying a dbt model or SQL pipeline, use it to surface table health, lineage, active alerts, and to generate monitors-as-code without leaving Claude Code.
Monte Carlo tool routing (required): Always call Monte Carlo MCP tools through this plugin's bundled server, whose fully-qualified tool names are
mcp__plugin_mc-agent-toolkit_monte-carlo-mcp__<tool>(e.g.mcp__plugin_mc-agent-toolkit_monte-carlo-mcp__get_alerts). Bare tool names used in this skill (get_alerts,search,get_table, …) refer to that bundled server. If the session also has a separately-configuredmonte-carlo-mcpserver, do not route to it — it may point at a different endpoint or credentials.
Reference files live next to this skill file. Use the Read tool (not MCP resources) to access them:
- Full workflow step-by-step instructions:
references/workflows.md(relative to this file) - MCP parameter details:
references/parameters.md(relative to this file) - Troubleshooting:
references/TROUBLESHOOTING.md(relative to this file)
When to activate this skill
Prevent is the edit-lifecycle skill. Activate only when the user expresses
intent to change a dbt model. Bare file mentions, table-name mentions in
passing, or general health questions are not prevent's territory — those
belong to monte-carlo-asset-health and will activate that skill on their own.
Do not wait to be asked. Run the appropriate workflow automatically whenever the user:
- Describes a planned change to a model (new column, join update, filter change, refactor) → STOP — run Workflow 1 first if it has not run for this table this session, then Workflow 2, before writing any code
- Adds a new column, metric, or output expression to an existing model → same rule: Workflow 1 first (if not yet run for this table), then Workflow 2; the post-edit hook will offer Workflow 5 (monitor generation) afterward
- References a model file with an edit verb in the same prompt (e.g.
@models/clients/client_hub.sql add an is_active column) → same rule: Workflow 1 first, then Workflow 2
What ships with it
16 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.
- README.md 8.1 KB
- references/parameters.md 1.0 KB
- references/TROUBLESHOOTING.md 1.5 KB
- references/workflows.md 36 KB
- scripts/sandbox/classify_sandbox.py 1.5 KB runs code
- scripts/sandbox/detect_hardcoded_db.py 1.2 KB runs code
- scripts/sandbox/parse_profiles.py 3.3 KB runs code
- scripts/sandbox/readonly_check.py 2.3 KB runs code
- scripts/sandbox/substitute_placeholders.py 3.7 KB runs code
- scripts/sandbox/tests/conftest.py 256 B runs code
- scripts/sandbox/tests/test_classify_sandbox.py 1.1 KB runs code
- scripts/sandbox/tests/test_detect_hardcoded_db.py 1.6 KB runs code
- scripts/sandbox/tests/test_integration_smoke.py 2.8 KB runs code
- scripts/sandbox/tests/test_parse_profiles.py 3.1 KB runs code
- scripts/sandbox/tests/test_readonly_check.py 3.9 KB runs code
- scripts/sandbox/tests/test_substitute_placeholders.py 3.7 KB runs code
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.
- 1mo ago First seen · 325 lines · 52 tokens per session scan A 3b7df6088641
monte-carlo-prevent is a skill published in the GitHub repository monte-carlo-data/mc-agent-toolkit (93 stars, last pushed yesterday), licensed Apache-2.0. It adds 52 tokens to every session and 4,243 once invoked, about $0.0002 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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