Switch to a different database.
AI agents invoke mysql_use_database to trigger actions in Mysql. 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.
Switching the active database context is not a pure read operation; it changes session state and affects all subsequent queries executed in that session. This is an Execute-level action because it alters the operational context of the database connection, potentially redirecting subsequent queries to a different (possibly sensitive) database.
From the tool's definition 'Switch to a different database' — changes the active database context for the session, triggering an external state change in the MySQL connection
Documented attack patterns abuse exactly the kind of access mysql_use_database gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Mysql, and nothing reaches the server without passing your rules. This is the rule we recommend for mysql_use_database:
{
"version": "1",
"default": "deny",
"tools": {
"mysql_use_database": {
"limits": [
{
"counter": "mysql_use_database_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}mysql_use_database 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.
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Switch to a different database. It is categorised as a Execute tool in the Mysql MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Mysql MCP server in PolicyLayer and add a rule for mysql_use_database: 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. Nothing to install.
mysql_use_database is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the mysql_use_database 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.
Set action: deny in the PolicyLayer policy for mysql_use_database. 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.
mysql_use_database is provided by the Mysql MCP server (mukul975/mysql-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Mysql, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
233 Mysql tools catalogued and risk-classified — across an index of 43,000+ MCP servers.