chart_set_symbol · TradingView MCP: Risk & Policy

WHAT IT DOES

What chart_set_symbol does on TradingView MCP

AI agents use chart_set_symbol to create or update resources in TradingView MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your TradingView MCP environment.

WHY IT NEEDS A POLICY

Why chart_set_symbol needs a policy

The tool modifies application state by changing the displayed symbol on a TradingView chart. This is categorized as Write because it creates or modifies data/configuration reversibly—users can simply change the symbol again to revert. It is not Read (no query-only), not Execute (doesn't run arbitrary code or trigger external trading), and not Destructive (the change is easily undone).

From the tool's definition Tool name 'chart_set_symbol' and description 'Change the chart symbol' indicate modification of chart state. This is a reversible write operation that alters which financial instrument is displayed.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

chart_set_symbol Rate-limited

chart_set_symbol stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "chart_set_symbol": {
      "limits": [
        {
          "counter": "chart_set_symbol_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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, so you can run agents against it safely.

FAQ

Questions about chart_set_symbol

What does the chart_set_symbol tool do? +

Change the chart symbol. It is categorised as a Write tool in the TradingView MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on chart_set_symbol? +

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

What risk level is chart_set_symbol? +

chart_set_symbol is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit chart_set_symbol? +

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

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

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