Fetch a URL and extract OpenGraph + Twitter Card + standard meta tags: og:title, og:description, og:image, og:type, twitter:card, twitter:image, canonical link, favicon, JSON-LD blocks. Use when an agent needs to preview a link before sharing, build a citation card, or detect spam/ads via meta-ta...
Risk signalsAccepts URL/endpoint input (url)
Part of the Onyx Mcp server.
Free to start. No card required.
AI agents invoke onyx_html_meta to trigger processes or run actions in Onyx Mcp. Execute operations can have side effects beyond the immediate call -- triggering builds, sending notifications, or starting workflows. Rate limits and argument validation are essential to prevent runaway execution.
onyx_html_meta can trigger processes with real-world consequences. An uncontrolled agent might start dozens of builds, send mass notifications, or kick off expensive compute jobs. PolicyLayer enforces rate limits and validates arguments to keep execution within safe bounds.
Execute tools trigger processes. Rate-limit and validate arguments to prevent unintended side effects.
{
"version": "1",
"default": "deny",
"tools": {
"onyx_html_meta": {
"limits": [
{
"counter": "onyx_html_meta_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}See the full Onyx Mcp policy for all 67 tools.
These attack patterns abuse exactly the kind of access onyx_html_meta gives an agent. Each links to the full case and the policy that stops it:
Other execute tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
Fetch a URL and extract OpenGraph + Twitter Card + standard meta tags: og:title, og:description, og:image, og:type, twitter:card, twitter:image, canonical link, favicon, JSON-LD blocks. Use when an agent needs to preview a link before sharing, build a citation card, or detect spam/ads via meta-tag fingerprints. Stripped of HTML noise. ~150-500ms typical. (price: $0.002 USDC, tier: metered). It is categorised as a Execute tool in the Onyx Mcp MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Onyx MCP server in PolicyLayer and add a rule for onyx_html_meta: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Onyx Mcp. Nothing to install.
onyx_html_meta is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the onyx_html_meta rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for onyx_html_meta. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
onyx_html_meta is provided by the Onyx MCP server (https://onyx-actions.onrender.com/mcp/). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 67 Onyx Mcp tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.