sql_query · MCP MySQL App MCP: Risk & Policy

WHAT IT DOES

What sql_query does on MCP MySQL App

AI agents invoke sql_query to trigger actions in MCP MySQL App. 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 sql_query needs a policy

This tool runs arbitrary SQL against a MySQL database. It can perform SELECT, INSERT, UPDATE, DELETE, DROP, and other DDL/DML operations depending on what query is passed. Since it spans Read, Write, Destructive, and Execute categories, the most severe applicable category is Execute (potentially Destructive).

From the tool's definition 'Executes operations against a MySQL database' — arbitrary SQL execution with no stated restrictions

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

sql_query Rate-limited

sql_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": {
    "sql_query": {
      "limits": [
        {
          "counter": "sql_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 MCP MySQL App, so you can run agents against it safely.

FAQ

Questions about sql_query

What does the sql_query tool do? +

Executes operations against a MySQL database. It is categorised as a Execute tool in the MCP MySQL App MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on sql_query? +

Register the MCP MySQL App MCP server in PolicyLayer and add a rule for sql_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 MCP MySQL App. Nothing to install.

What risk level is sql_query? +

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

Can I rate-limit sql_query? +

Yes. Add a rate_limit block to the sql_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 sql_query completely? +

Set action: deny in the PolicyLayer policy for sql_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 sql_query? +

sql_query is provided by the MCP MySQL App MCP server (zalab-inc/mcp-mysql-app). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

// THE FULL RECORD

sql_query is one line of MCP MySQL App's registry record.

The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.

Teams ship this data inside their own products. See what a licence covers →