Lock tables for the current session.
AI agents invoke mysql_lock_tables 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.
Locking tables is an operational action that affects database availability and concurrency for other sessions. While it doesn't delete or modify data directly, it executes a database-level operation that can block other users/processes from accessing tables, potentially causing outages or deadlocks.
From the tool's definition Lock tables for the current session
Documented attack patterns abuse exactly the kind of access mysql_lock_tables 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_lock_tables:
{
"version": "1",
"default": "deny",
"tools": {
"mysql_lock_tables": {
"limits": [
{
"counter": "mysql_lock_tables_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}mysql_lock_tables 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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Lock tables for the current session. 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_lock_tables: 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_lock_tables 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_lock_tables 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_lock_tables. 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_lock_tables 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.
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233 Mysql tools catalogued and risk-classified — across an index of 43,000+ MCP servers.