mysql_query · FastMCP MySQL Server MCP: Risk & Policy

WHAT IT DOES

What mysql_query does on FastMCP MySQL Server

AI agents invoke mysql_query to trigger actions in FastMCP MySQL 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 mysql_query needs a policy

The tool name strongly implies SQL query execution. The server description confirms it executes SQL queries, with optional write permissions. Since the tool could execute arbitrary SQL (including writes or destructive statements if write permissions are enabled), Execute is the most appropriate category. Severity is high due to potential for data modification or exposure.

From the tool's definition Tool name 'mysql_query' and server description states 'enabling LLMs to execute SQL queries with read-only access by default and optional write permissions'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

mysql_query Rate-limited

mysql_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": {
    "mysql_query": {
      "limits": [
        {
          "counter": "mysql_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 FastMCP MySQL Server, so you can run agents against it safely.

FAQ

Questions about mysql_query

What does the mysql_query tool do? +

mysql_query. It is categorised as a Execute tool in the FastMCP MySQL 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 mysql_query? +

Register the FastMCP MySQL Server MCP server in PolicyLayer and add a rule for mysql_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 FastMCP MySQL Server. Nothing to install.

What risk level is mysql_query? +

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

Can I rate-limit mysql_query? +

Yes. Add a rate_limit block to the mysql_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 mysql_query completely? +

Set action: deny in the PolicyLayer policy for mysql_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 mysql_query? +

mysql_query is provided by the FastMCP MySQL Server MCP server (jinto/fastmcp-mysql). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.