custom_jql · Mixpanel MCP: Risk & Policy

WHAT IT DOES

What custom_jql does on Mixpanel MCP

AI agents invoke custom_jql to trigger actions in Mixpanel MCP. 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 custom_jql needs a policy

This tool allows execution of arbitrary query language commands (JQL) whose effects depend entirely on the arguments provided by the user or AI agent. While the queries appear to be read-only analytics operations (based on the sibling tools being queries and reports), the ability to run 'custom' and 'advanced' queries means the tool can potentially access any data the Mixpanel account exposes, create derived data,…

From the tool's definition Tool name 'custom_jql' and description explicitly states 'Run custom JQL (JSON Query Language) queries', indicating execution of user-supplied query language code against the Mixpanel analytics backend.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

custom_jql Rate-limited

custom_jql 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": {
    "custom_jql": {
      "limits": [
        {
          "counter": "custom_jql_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 Mixpanel MCP, so you can run agents against it safely.

FAQ

Questions about custom_jql

What does the custom_jql tool do? +

Run custom JQL (JSON Query Language) queries. Useful for advanced analytics and custom data analysis beyond standard reports. It is categorised as a Execute tool in the Mixpanel MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on custom_jql? +

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

What risk level is custom_jql? +

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

Can I rate-limit custom_jql? +

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

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

custom_jql is provided by the Mixpanel MCP server (mendeel/mixpanel-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.