execute_query · Vertica MCP Server MCP: Risk & Policy

WHAT IT DOES

What execute_query does on Vertica MCP Server

AI agents invoke execute_query 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 needs a policy

This tool executes arbitrary SQL queries against a live database. Although the restriction to SELECT/DESCRIBE/EXPLAIN prevents destructive or write operations, the ability to execute any query in these categories constitutes Execute risk rather than Read, because: (1) query execution can have side effects beyond data retrieval (e.g., logging, monitoring triggers, performance impact), (2) AI agents could construct…

From the tool's definition Tool description states it 'Execute[s] a SQL query against the Vertica database' and explicitly allows 'SELECT, DESCRIBE, and EXPLAIN statements.' The verb 'execute' combined with SQL query execution capabilities indicates code/query execution.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

execute_query Rate-limited

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

FAQ

Questions about execute_query

What does the execute_query tool do? +

Execute a SQL query against the Vertica database. Only SELECT, DESCRIBE, and EXPLAIN statements are allowed for safety. 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? +

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

What risk level is execute_query? +

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

Can I rate-limit execute_query? +

Yes. Add a rate_limit block to the execute_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 execute_query completely? +

Set action: deny in the PolicyLayer policy for execute_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 execute_query? +

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