mysql_query

THE RISK

Low Risk

Why mysql_query needs a policy

This tool is designed for retrieving data only. SELECT queries cannot modify, delete, or destroy data—they only fetch existing records. The explicit 'read-only' constraint in the description ensures no side effects.

From the tool's definition Tool name is 'mysql_query' and description explicitly states 'Execute read-only SELECT queries against the MySQL database.' The description confirms this is limited to SELECT operations with no write, delete, or other data-modification capabilities.

Documented attack patterns abuse exactly the kind of access mysql_query gives an agent:

POLICY

How to control mysql_query

PolicyLayer is an MCP gateway — it sits between your AI agents and MySQL MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for mysql_query:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "mysql_query": {}
  }
}

mysql_query is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

Create a free account and register MySQL MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

CAP THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More MySQL MCP Server tools

Execute mysql_execute Execute data modification queries (INSERT/UPDATE/DELETE).\n Read describe_table Show table structure Read list_tables List all tables in current database

All 4 MySQL MCP Server tools →

Read tools on other servers

M-Team MCP Server get_torrent_detail YouTube MCP Server search_channel Android Forensics ADB MCP Server parse_browser_history 0xarchive web3_challenge

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about mysql_query

What does the mysql_query tool do? +

Execute read-only SELECT queries against the MySQL database.\n. It is categorised as a Read tool in the MySQL MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on mysql_query? +

Register the MySQL MCP 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 MySQL MCP Server. Nothing to install.

What risk level is mysql_query? +

mysql_query is a Read tool with low risk. Read-only tools are generally safe to allow by default.

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 MySQL MCP Server MCP server (kevinwatt/mysql-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every MySQL MCP Server tool call.

Start from MySQL MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →