pg_unused_indexes

Find indexes that have never been used (idx_scan = 0). Candidates for removal.

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-unused-indexes.md

WHAT IT DOES

What pg_unused_indexes does on PostgreSQL MCP Server

AI agents call pg_unused_indexes 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_unused_indexes is rated Low

The tool performs a diagnostic read operation that queries system metadata (pg_stat_user_indexes or similar) to identify unused indexes. It does not modify, delete, or execute any changes; it only retrieves and reports information to support decision-making. The phrase 'Candidates for removal' refers to what an administrator might do afterward, not what the tool itself does.

From the tool's definition Tool description states it "Find[s] indexes that have never been used" and queries the idx_scan metric to identify candidates. This is a query/retrieval operation with no modifications to data or schema.

Attacks that exploit this kind of access

RECOMMENDED RULE

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

pg_unused_indexes Allowed

pg_unused_indexes 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_unused_indexes": {}
  }
}

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_unused_indexes call is checked against it from then on.

FAQ

Questions about pg_unused_indexes

What does the pg_unused_indexes tool do? +

Find indexes that have never been used (idx_scan = 0). Candidates for removal. 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_unused_indexes? +

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

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

Can I rate-limit pg_unused_indexes? +

Yes. Add a rate_limit block to the pg_unused_indexes 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_unused_indexes completely? +

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

pg_unused_indexes 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_unused_indexes does on PostgreSQL MCP Server

Why pg_unused_indexes is rated Low

The rule that runs pg_unused_indexes safely

Questions about pg_unused_indexes

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