list_objects

List tables, views, materialized views, sequences, or extensions in a schema. Requires active connection. Optionally use server/database/targetSchema params for one-time execution on a different server.

Server Postgres teja-sudo/postgres-mcp-server
Category Read
Risk class Low
Parameters 00 required

What list_objects does on Postgres

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

Why list_objects needs a policy

This tool performs schema introspection and metadata discovery only. It retrieves structural information about database objects without modifying, executing, or deleting anything. The blast radius of misuse is minimal—an attacker gains information about database structure but cannot alter data, execute queries, or cause damage. This is a standard read-only operation typical of database exploration tools.

From the tool's definition Tool lists tables, views, materialized views, sequences, or extensions in a schema - pure retrieval operations with no data modification, execution, or destructive capabilities.

Questions about list_objects

What does the list_objects tool do? +

List tables, views, materialized views, sequences, or extensions in a schema. Requires active connection. Optionally use server/database/targetSchema params for one-time execution on a different server. It is categorised as a Read tool in the Postgres MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on list_objects? +

Register the Postgres MCP server in PolicyLayer and add a rule for list_objects: 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 Postgres. Nothing to install.

What risk level is list_objects? +

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

Can I rate-limit list_objects? +

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

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

list_objects is provided by the Postgres MCP server (teja-sudo/postgres-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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