use_connection · MySQL MCP Server MCP: Risk & Policy

WHAT IT DOES

What use_connection does on MySQL MCP Server

AI agents invoke use_connection to trigger actions in MySQL MCP 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 use_connection needs a policy

This tool switches the active database connection context. It doesn't read, write, or delete data directly, but it executes a state change that affects which database all subsequent operations run against. Misuse could redirect an AI agent to operate on an unintended database, potentially amplifying the blast radius of other tools. This is an operational/execution action with moderate severity.

From the tool's definition 切换活动连接（MYSQL_MCP_CONNECTION_ID）；需先在 MYSQL_MCP_EXTRA_CONNECTIONS 配置额外 DSN

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

use_connection Rate-limited

use_connection 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": {
    "use_connection": {
      "limits": [
        {
          "counter": "use_connection_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 MySQL MCP Server, so you can run agents against it safely.

FAQ

Questions about use_connection

What does the use_connection tool do? +

切换活动连接（MYSQL_MCP_CONNECTION_ID）；需先在 MYSQL_MCP_EXTRA_CONNECTIONS 配置额外 DSN. It is categorised as a Execute tool in the MySQL MCP 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 use_connection? +

Register the MySQL MCP Server MCP server in PolicyLayer and add a rule for use_connection: 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 use_connection? +

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

Can I rate-limit use_connection? +

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

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

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