execute_query_stream · Vertica MCP Server MCP: Risk & Policy

WHAT IT DOES

What execute_query_stream does on Vertica MCP Server

AI agents invoke execute_query_stream to trigger actions in Vertica 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 execute_query_stream needs a policy

execute_query_stream 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

execute_query_stream Rate-limited

execute_query_stream 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": {
    "execute_query_stream": {
      "limits": [
        {
          "counter": "execute_query_stream_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 Vertica MCP Server, so you can run agents against it safely.

FAQ

Questions about execute_query_stream

What does the execute_query_stream tool do? +

Stream query results with batching and size limits. It is categorised as a Execute tool in the Vertica 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 execute_query_stream? +

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

What risk level is execute_query_stream? +

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

Can I rate-limit execute_query_stream? +

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

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

execute_query_stream is provided by the Vertica MCP Server MCP server (zaboura/vertica-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.