query_loki_logs

THE RISK

High Risk

Why query_loki_logs needs a policy

The tool actively executes a query (LogQL) against an external Loki datasource. While it primarily retrieves log data (read-like behavior), it runs arbitrary query logic against an external system, placing it in the Execute category. Misuse could expose sensitive log data or cause performance issues on the Loki instance with expensive queries, warranting medium severity.

From the tool's definition "Execute a LogQL query against a Loki datasource" — the tool runs an arbitrary LogQL query against an external system

Documented attack patterns abuse exactly the kind of access query_loki_logs gives an agent:

POLICY

How to control query_loki_logs

PolicyLayer is an MCP gateway — it sits between your AI agents and Grafana FastMCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for query_loki_logs:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "query_loki_logs": {
      "limits": [
        {
          "counter": "query_loki_logs_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

query_loki_logs 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.

Create a free account and register Grafana FastMCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RATE-LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Grafana FastMCP Server tools

Execute find_error_pattern_logs Run the ErrorPatternLogs check via Sift and return the analysis result. Execute find_slow_requests Run the SlowRequests check via Sift and return the analysis result. Execute query_prometheus Execute PromQL queries against a Prometheus datasource. Write add_activity_to_incident Add a user note to an incident Write create_incident Create a new Grafana incident with the provided details. Write update_dashboard update_dashboard Read fetch fetch Read fetch_pyroscope_profile Fetch a Pyroscope profile in DOT format for a given query.

All 45 Grafana FastMCP Server tools →

Execute tools on other servers

Android Forensics ADB MCP Server adb_shell_command EMBA-MCP run_emba_scan Frida Game Hacking MCP remove_breakpoint Procmon request_elevation

Go deeper

High-risk tools in Grafana FastMCP Server → Every high-risk tool this server exposes, in one view.
All high-risk MCP tools → Every high-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Agent sandbox → Bounding what an agent can execute and where the boundary should sit.
Least privilege for MCP → Granting agents the minimum tool surface the task needs.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about query_loki_logs

What does the query_loki_logs tool do? +

Execute a LogQL query against a Loki datasource and return the matching log entries. It is categorised as a Execute tool in the Grafana FastMCP 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 query_loki_logs? +

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

What risk level is query_loki_logs? +

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

Can I rate-limit query_loki_logs? +

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

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

query_loki_logs is provided by the Grafana FastMCP Server MCP server (sandersouza/grafanafastmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Grafana FastMCP Server tool call.

Start from Grafana FastMCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →