cancel_query · Imply Druid MCP: Risk & Policy

WHAT IT DOES

What cancel_query does on Imply Druid

AI agents invoke cancel_query to trigger actions in Imply Druid. 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 cancel_query needs a policy

Cancelling a query triggers an external server-side operation (aborting an executing query). It is not purely read-only, nor does it delete data, but it does actively interrupt a running process. This falls under Execute as it triggers an external operation. Severity is medium because misuse could disrupt legitimate queries but has no data-loss or financial impact.

From the tool's definition Cancel a running query — terminates an in-progress operation on the server.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

cancel_query Rate-limited

cancel_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": {
    "cancel_query": {
      "limits": [
        {
          "counter": "cancel_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 Imply Druid, so you can run agents against it safely.

FAQ

Questions about cancel_query

What does the cancel_query tool do? +

Cancel a running query. It is categorised as a Execute tool in the Imply Druid MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on cancel_query? +

Register the Imply Druid MCP server in PolicyLayer and add a rule for cancel_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 Imply Druid. Nothing to install.

What risk level is cancel_query? +

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

Can I rate-limit cancel_query? +

Yes. Add a rate_limit block to the cancel_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 cancel_query completely? +

Set action: deny in the PolicyLayer policy for cancel_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 cancel_query? +

cancel_query is provided by the Imply Druid MCP server (yeongbin-hwang/imply-druid-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.