prometheus_query · Lumino MCP Server MCP: Risk & Policy

WHAT IT DOES

What prometheus_query does on Lumino MCP Server

AI agents invoke prometheus_query to trigger actions in Lumino 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 prometheus_query needs a policy

The tool name suggests it executes queries against Prometheus, a metrics/monitoring system. Query execution tools can have significant impact depending on the query (e.g., expensive queries can impact cluster performance). Without a description, we cannot confirm read-only behavior, so we conservatively classify as Execute given the query execution nature. Confidence is reduced due to empty description.

From the tool's definition Tool name is 'prometheus_query'; description is empty or uninformative.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

prometheus_query Rate-limited

prometheus_query 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": {
    "prometheus_query": {
      "limits": [
        {
          "counter": "prometheus_query_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 Lumino MCP Server, so you can run agents against it safely.

FAQ

Questions about prometheus_query

What does the prometheus_query tool do? +

prometheus_query. It is categorised as a Execute tool in the Lumino 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 prometheus_query? +

Register the Lumino MCP Server MCP server in PolicyLayer and add a rule for prometheus_query: 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 Lumino MCP Server. Nothing to install.

What risk level is prometheus_query? +

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

Can I rate-limit prometheus_query? +

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

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

prometheus_query is provided by the Lumino MCP Server MCP server (lumino-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.