evaluate-script · TgeBrowser MCP Server MCP: Risk & Policy

WHAT IT DOES

What evaluate-script does on TgeBrowser MCP Server

AI agents invoke evaluate-script to trigger actions in TgeBrowser 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 evaluate-script needs a policy

Evaluating/executing scripts in a browser context can run arbitrary JavaScript, access browser state, exfiltrate data, interact with web pages, or perform any browser-based action. This is an Execute category tool with high severity due to the open-ended nature of arbitrary script execution in a live browser environment.

From the tool's definition Tool name 'evaluate-script' and description 'Evaluate the script' indicate execution of arbitrary script code within a browser environment.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

evaluate-script Rate-limited

evaluate-script 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": {
    "evaluate-script": {
      "limits": [
        {
          "counter": "evaluate-script_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 TgeBrowser MCP Server, so you can run agents against it safely.

FAQ

Questions about evaluate-script

What does the evaluate-script tool do? +

Evaluate the script. It is categorised as a Execute tool in the TgeBrowser 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 evaluate-script? +

Register the TgeBrowser MCP Server MCP server in PolicyLayer and add a rule for evaluate-script: 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 TgeBrowser MCP Server. Nothing to install.

What risk level is evaluate-script? +

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

Can I rate-limit evaluate-script? +

Yes. Add a rate_limit block to the evaluate-script 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 evaluate-script completely? +

Set action: deny in the PolicyLayer policy for evaluate-script. 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 evaluate-script? +

evaluate-script is provided by the TgeBrowser MCP Server MCP server (tuguang2025/tgebrowser-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.