Explain table structure (alias for DESCRIBE).
AI agents call explain_table to retrieve information from Mysql without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool executes a DESCRIBE/EXPLAIN statement to inspect table structure and schema information. It has no side effects, does not modify data, and does not execute arbitrary code. The server description emphasizes 'read-only queries' which aligns with this classification.
From the tool's definition Tool name 'explain_table' with description 'Explain table structure (alias for DESCRIBE)' - DESCRIBE is a read-only SQL command that retrieves schema metadata without modifying data.
Documented attack patterns abuse exactly the kind of access explain_table 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 explain_table:
{
"version": "1",
"default": "deny",
"tools": {
"explain_table": {}
}
}explain_table is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Explain table structure (alias for DESCRIBE). It is categorised as a Read tool in the Mysql MCP Server, which means it retrieves data without modifying state.
Register the Mysql MCP server in PolicyLayer and add a rule for explain_table: 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.
explain_table is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the explain_table 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 explain_table. 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.
explain_table 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.