query

Execute a read-only SQL query against the PostgreSQL database. Use this for SELECT, SHOW, EXPLAIN statements.

SERVERPostgreSQL MCP Server SOURCEaeiyannn/postgree-mcp

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade C, identity unverified Pull the record →

This record as markdown: /tools/aeiyannn-postgree-mcp/query.md

WHAT IT DOES

What query does on PostgreSQL MCP Server

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

RISK

Why query is rated Low

This tool is constrained to read-only SQL operations (SELECT, SHOW, EXPLAIN) with no data modification, deletion, or external side effects. The main risk is information disclosure if the database contains sensitive data, but the tool itself cannot modify state. Severity is low because the blast radius is limited to data exposure rather than system compromise or data loss.

From the tool's definition Tool description explicitly states 'Execute a read-only SQL query' and restricts usage to 'SELECT, SHOW, EXPLAIN statements' which are non-destructive query operations.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs query safely

PolicyLayer is an MCP gateway: it sits between your AI agents and PostgreSQL MCP Server, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For query, this is the rule to start with:

query Allowed

query is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "query": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect PostgreSQL MCP Server, apply this rule, and every query call is checked against it from then on.

FAQ

Questions about query

What does the query tool do? +

Execute a read-only SQL query against the PostgreSQL database. Use this for SELECT, SHOW, EXPLAIN statements. It is categorised as a Read tool in the PostgreSQL MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on query? +

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

What risk level is query? +

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

Can I rate-limit query? +

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

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

query is provided by the PostgreSQL MCP Server MCP server (aeiyannn/postgree-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

What query does on PostgreSQL MCP Server

Why query is rated Low

The rule that runs query safely

Questions about query

More on PostgreSQL MCP Server, and thousands of servers like it.