Low Risk

get_render_blocking_details

Get render-blocking resources and critical request chains showing loading dependencies

How to control get_render_blocking_details ↓

AI agents call get_render_blocking_details to retrieve information from PageSpeed Insights MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

Low Risk

Even though get_render_blocking_details only reads data, uncontrolled read access leaks sensitive information and racks up API costs — an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.

Documented attack patterns abuse exactly the kind of access get_render_blocking_details gives an agent:

PolicyLayer is an MCP gateway — it sits between your AI agents and PageSpeed Insights MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for get_render_blocking_details:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "get_render_blocking_details": {}
  }
}

get_render_blocking_details is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

  1. Create a free account and register PageSpeed Insights MCP Server — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
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Go deeper

What does the get_render_blocking_details tool do? +

Get render-blocking resources and critical request chains showing loading dependencies. It is categorised as a Read tool in the PageSpeed Insights MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on get_render_blocking_details? +

Register the PageSpeed Insights MCP Server MCP server in PolicyLayer and add a rule for get_render_blocking_details: 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 PageSpeed Insights MCP Server. Nothing to install.

What risk level is get_render_blocking_details? +

get_render_blocking_details is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit get_render_blocking_details? +

Yes. Add a rate_limit block to the get_render_blocking_details 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.

How do I block get_render_blocking_details completely? +

Set action: deny in the PolicyLayer policy for get_render_blocking_details. 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.

What MCP server provides get_render_blocking_details? +

get_render_blocking_details is provided by the PageSpeed Insights MCP Server MCP server (ruslanlap/pagespeed-insights-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every PageSpeed Insights MCP Server tool call.

Deterministic rules across all 16 PageSpeed Insights MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.

Free to start. No card required.

16 PageSpeed Insights MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.

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