ui_evaluate · TradingView MCP Jackson MCP: Risk & Policy

WHAT IT DOES

What ui_evaluate does on TradingView MCP Jackson

AI agents invoke ui_evaluate to trigger actions in TradingView MCP Jackson. 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 ui_evaluate needs a policy

This tool directly executes code within the TradingView application environment. JavaScript execution in a browser context is inherently an Execute-category action because it can run arbitrary logic whose effects depend entirely on the JavaScript provided.

From the tool's definition Tool description explicitly states 'Execute JavaScript code in the TradingView page context for advanced automation'.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

ui_evaluate Rate-limited

ui_evaluate 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": {
    "ui_evaluate": {
      "limits": [
        {
          "counter": "ui_evaluate_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 TradingView MCP Jackson, so you can run agents against it safely.

FAQ

Questions about ui_evaluate

What does the ui_evaluate tool do? +

Execute JavaScript code in the TradingView page context for advanced automation. It is categorised as a Execute tool in the TradingView MCP Jackson MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on ui_evaluate? +

Register the TradingView MCP Jackson MCP server in PolicyLayer and add a rule for ui_evaluate: 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 TradingView MCP Jackson. Nothing to install.

What risk level is ui_evaluate? +

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

Can I rate-limit ui_evaluate? +

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

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

ui_evaluate is provided by the TradingView MCP Jackson MCP server (nimit791/tradingview-mcp-jackson). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.