fleet_verdict · Grafana MCP Server MCP: Risk & Policy

WHAT IT DOES

What fleet_verdict does on Grafana MCP Server

AI agents invoke fleet_verdict to trigger actions in Grafana 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 fleet_verdict needs a policy

The tool executes a performance assessment operation across multiple sensors concurrently ('in parallel'). While not destructive and not modifying data, it triggers active operations against external systems (sensors), which qualifies as Execute rather than Read. Severity is medium because the blast radius is limited to diagnostic/performance assessment operations without direct data modification or financial impact.

From the tool's definition Tool name and description indicate running a performance verdict 'against all discovered sensors in parallel', which involves triggering external operations whose effects depend on sensor state and configuration.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

fleet_verdict Rate-limited

fleet_verdict 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": {
    "fleet_verdict": {
      "limits": [
        {
          "counter": "fleet_verdict_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 Grafana MCP Server, so you can run agents against it safely.

FAQ

Questions about fleet_verdict

What does the fleet_verdict tool do? +

Run performance verdict against all discovered sensors in parallel. Returns per-sensor results and fleet summary. It is categorised as a Execute tool in the Grafana 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 fleet_verdict? +

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

What risk level is fleet_verdict? +

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

Can I rate-limit fleet_verdict? +

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

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

fleet_verdict is provided by the Grafana MCP Server MCP server (quanticsoul4772/grafana-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.