dry_run_query · BigQuery MCP Server MCP: Risk & Policy

WHAT IT DOES

What dry_run_query does on BigQuery MCP Server

AI agents invoke dry_run_query to trigger actions in BigQuery 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 dry_run_query needs a policy

dry_run_query triggers real processes with real consequences. An agent gone sideways doesn't fire it once — it starts dozens of builds, sends mass notifications, or burns through compute before anyone looks up.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

dry_run_query Rate-limited

dry_run_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": {
    "dry_run_query": {
      "limits": [
        {
          "counter": "dry_run_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 BigQuery MCP Server, so you can run agents against it safely.

FAQ

Questions about dry_run_query

What does the dry_run_query tool do? +

Check query for errors and estimate cost without executing it. It is categorised as a Execute tool in the BigQuery 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 dry_run_query? +

Register the BigQuery MCP Server MCP server in PolicyLayer and add a rule for dry_run_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 BigQuery MCP Server. Nothing to install.

What risk level is dry_run_query? +

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

Can I rate-limit dry_run_query? +

Yes. Add a rate_limit block to the dry_run_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 dry_run_query completely? +

Set action: deny in the PolicyLayer policy for dry_run_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 dry_run_query? +

dry_run_query is provided by the BigQuery MCP Server MCP server (takuya0206/bigquery-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.