postgres_tool · Multi-Server MCP Project MCP: Risk & Policy

WHAT IT DOES

What postgres_tool does on Multi-Server MCP Project

AI agents invoke postgres_tool to trigger actions in Multi-Server MCP Project. 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 postgres_tool needs a policy

This tool executes arbitrary SQL, which could include SELECT (Read), INSERT/UPDATE (Write), DELETE/DROP (Destructive), or any other SQL command. Since the tool description imposes no restrictions on query type, the most severe applicable category is Execute (with Destructive potential). An AI agent could misuse this to run DROP TABLE, DELETE FROM, or other irreversible operations, making the blast radius critical.

From the tool's definition 'Executes a SQL query on a PostgreSQL database' — runs arbitrary SQL statements against a live PostgreSQL database

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

postgres_tool Rate-limited

postgres_tool 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": {
    "postgres_tool": {
      "limits": [
        {
          "counter": "postgres_tool_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 Multi-Server MCP Project, so you can run agents against it safely.

FAQ

Questions about postgres_tool

What does the postgres_tool tool do? +

Executes a SQL query on a PostgreSQL database and returns the results. It is categorised as a Execute tool in the Multi-Server MCP Project MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on postgres_tool? +

Register the Multi-Server MCP Project MCP server in PolicyLayer and add a rule for postgres_tool: 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 Multi-Server MCP Project. Nothing to install.

What risk level is postgres_tool? +

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

Can I rate-limit postgres_tool? +

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

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

postgres_tool is provided by the Multi-Server MCP Project MCP server (srinikandula/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.