list_permissions

Discover privileges granted to roles on schemas, tables, and columns (FR-002c)

SERVERPostgres SOURCE@allensandiego/postgres-mcp-server

Low RISK CLASS

Category Read

Parameters 30 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/allensandiego-postgres-mcp-server/list-permissions.md

WHAT IT DOES

What list_permissions does on Postgres

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

Parameter	Type	Required	Description
`table`	string	—	Optional table filter
`schema`	string	—	Optional schema filter (e.g. 'public')
`objectType`	string	—	Optional object type filter: 'schema', 'table', or 'column'

Parameters from the server's own tool schema.

RISK

Why list_permissions is rated Low

Even though list_permissions only reads data, uncontrolled read access leaks sensitive information and racks up API costs: an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs list_permissions safely

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

list_permissions Allowed

list_permissions 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": {
    "list_permissions": {}
  }
}

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

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

FAQ

Questions about list_permissions

What does the list_permissions tool do? +

Discover privileges granted to roles on schemas, tables, and columns (FR-002c). It is categorised as a Read tool in the Postgres MCP Server, which means it retrieves data without modifying state.

What parameters does list_permissions accept? +

list_permissions accepts 3 parameters: table, schema, objectType. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on list_permissions? +

Register the Postgres MCP server in PolicyLayer and add a rule for list_permissions: 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_permissions? +

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

Can I rate-limit list_permissions? +

Yes. Add a rate_limit block to the list_permissions 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_permissions completely? +

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

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

KEEP EXPLORING

What list_permissions does on Postgres

Why list_permissions is rated Low

The rule that runs list_permissions safely

Questions about list_permissions

More on Postgres, and thousands of servers like it.