explainQuery · SQL MCP Server MCP: Risk & Policy

WHAT IT DOES

What explainQuery does on SQL MCP Server

AI agents call explainQuery to retrieve information from SQL MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

WHY IT NEEDS A POLICY

Why explainQuery needs a policy

explainQuery performs query analysis and explanation operations that retrieve metadata and execution plan information without executing the query against live data or modifying any database state. This is a classic Read operation—information retrieval with no side effects. The read-only designation in the description confirms low risk.

From the tool's definition Tool description states '只读' (read-only) and explains it outputs query metadata (tables, joins, filters, sorting, execution plan) without modifying data.

Attacks that exploit this kind of access

Questions about explainQuery

What does the explainQuery tool do? +

输出查询涉及的表/连接/过滤/排序与执行计划要点（只读）. It is categorised as a Read tool in the SQL MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on explainQuery? +

Register the SQL MCP Server MCP server in PolicyLayer and add a rule for explainQuery: 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 SQL MCP Server. Nothing to install.

What risk level is explainQuery? +

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

Can I rate-limit explainQuery? +

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

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

explainQuery is provided by the SQL MCP Server MCP server (polarisxb/sql-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.