update_postgres_role · CloudNativePG MCP Server MCP

WHAT IT DOES

What update_postgres_role does on CloudNativePG MCP Server

AI agents use update_postgres_role to create or update resources in CloudNativePG MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your CloudNativePG MCP Server environment.

WHY IT NEEDS A POLICY

Why update_postgres_role needs a policy

This tool modifies existing PostgreSQL role configurations and can reset passwords, which are reversible write operations. While password resets affect security posture, the operation itself is not destructive (roles aren't deleted) and doesn't execute arbitrary code or move money.

From the tool's definition Tool name 'update_postgres_role' and description 'Update an existing PostgreSQL role's attributes and optionally reset password' indicate modification of role properties and credentials.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_postgres_role Rate-limited

update_postgres_role stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "update_postgres_role": {
      "limits": [
        {
          "counter": "update_postgres_role_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches CloudNativePG MCP Server, so you can run agents against it safely.

FAQ

Questions about update_postgres_role

What does the update_postgres_role tool do? +

Update an existing PostgreSQL role's attributes and optionally reset password. It is categorised as a Write tool in the CloudNativePG MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_postgres_role? +

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

What risk level is update_postgres_role? +

update_postgres_role is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit update_postgres_role? +

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

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

update_postgres_role is provided by the CloudNativePG MCP Server MCP server (wateim/cnpg-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.