pg_explain

Show query execution plan without running the query.

SERVERPostgreSQL MCP Server SOURCE@neverinfamous/postgres-mcp

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-neverinfamous-postgres-mcp/pg-explain.md

WHAT IT DOES

What pg_explain does on PostgreSQL MCP Server

AI agents call pg_explain 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 pg_explain is rated Low

This tool retrieves and displays query execution plan information, which is a read-only operation with no side effects. It does not modify data, execute code with external effects, delete anything, or commit financial transactions. The explicit mention that it does not 'run the query' confirms it is purely informational retrieval.

From the tool's definition Tool name is 'pg_explain' and description states 'Show query execution plan without running the query.' The EXPLAIN command in PostgreSQL generates metadata about query execution without modifying or executing the query itself.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs pg_explain 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 pg_explain, this is the rule to start with:

pg_explain Allowed

pg_explain 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": {
    "pg_explain": {}
  }
}

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 pg_explain call is checked against it from then on.

FAQ

Questions about pg_explain

What does the pg_explain tool do? +

Show query execution plan without running the query. 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 pg_explain? +

Register the PostgreSQL MCP Server MCP server in PolicyLayer and add a rule for pg_explain: 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 pg_explain? +

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

Can I rate-limit pg_explain? +

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

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

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

KEEP EXPLORING

What pg_explain does on PostgreSQL MCP Server

Why pg_explain is rated Low

The rule that runs pg_explain safely

Questions about pg_explain

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