nl2sql · MCP Oracle Server MCP: Risk & Policy

WHAT IT DOES

What nl2sql does on MCP Oracle Server

AI agents invoke nl2sql to trigger actions in MCP Oracle 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 nl2sql needs a policy

This tool converts natural language into SQL and presumably executes it (or prepares it for execution via runQuery on the same server). The generated SQL is unpredictable and could include DML or DDL statements (INSERT, UPDATE, DELETE, DROP), making this an Execute-category risk at minimum. The reliance on an external service adds supply-chain risk.

From the tool's definition Convert natural language query to SQL using an external NL2SQL service

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

nl2sql Rate-limited

nl2sql 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": {
    "nl2sql": {
      "limits": [
        {
          "counter": "nl2sql_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 MCP Oracle Server, so you can run agents against it safely.

FAQ

Questions about nl2sql

What does the nl2sql tool do? +

Convert natural language query to SQL using an external NL2SQL service. The service should be running at the URL specified in NL2SQL_URL environment variable. It is categorised as a Execute tool in the MCP Oracle 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 nl2sql? +

Register the MCP Oracle Server MCP server in PolicyLayer and add a rule for nl2sql: 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 MCP Oracle Server. Nothing to install.

What risk level is nl2sql? +

nl2sql is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit nl2sql? +

Yes. Add a rate_limit block to the nl2sql 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 nl2sql completely? +

Set action: deny in the PolicyLayer policy for nl2sql. 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 nl2sql? +

nl2sql is provided by the MCP Oracle Server MCP server (jaikishpai/mcp-server-nodejs). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.