resize · Brave Browser MCP Server MCP: Risk & Policy

WHAT IT DOES

What resize does on Brave Browser MCP Server

AI agents invoke resize to trigger actions in Brave Browser MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why resize needs a policy

Resizing the browser viewport is an external operation that modifies the state of the browser environment. It doesn't read data, write persistent data, or destroy anything, but it does execute a browser-level action. The blast radius is low since it only affects display dimensions and is easily reversible.

From the tool's definition 'Resizes the browser viewport to the given width and height in pixels' — triggers an external browser operation affecting the viewport dimensions

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

resize Rate-limited

resize stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "resize": {
      "limits": [
        {
          "counter": "resize_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Brave Browser MCP Server, so you can run agents against it safely.

FAQ

Questions about resize

What does the resize tool do? +

Resizes the browser viewport to the given width and height in pixels. It is categorised as a Execute tool in the Brave Browser MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on resize? +

Register the Brave Browser MCP Server MCP server in PolicyLayer and add a rule for resize: 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 Brave Browser MCP Server. Nothing to install.

What risk level is resize? +

resize is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit resize? +

Yes. Add a rate_limit block to the resize 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 resize completely? +

Set action: deny in the PolicyLayer policy for resize. 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 resize? +

resize is provided by the Brave Browser MCP Server MCP server (slaveofgod1/brave-browser-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.