configure_masking · Postgres Safe MCP: Risk & Policy

WHAT IT DOES

What configure_masking does on Postgres Safe

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

WHY IT NEEDS A POLICY

Why configure_masking needs a policy

This tool creates or modifies masking rule configurations, which is a reversible state change (Write category). Severity is high because misconfiguring masking rules could expose PII that should be obfuscated, or over-mask legitimate data needed for operations.

From the tool's definition Tool name 'configure_masking' indicates modification of masking configuration rules. The server description references 'masking_rules' as a managed resource, and this tool would modify those rules that govern PII obfuscation behavior across all queries.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

configure_masking Rate-limited

configure_masking 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": {
    "configure_masking": {
      "limits": [
        {
          "counter": "configure_masking_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 Postgres Safe, so you can run agents against it safely.

FAQ

Questions about configure_masking

What does the configure_masking tool do? +

configure_masking. It is categorised as a Write tool in the Postgres Safe MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on configure_masking? +

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

What risk level is configure_masking? +

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

Can I rate-limit configure_masking? +

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

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

configure_masking is provided by the Postgres Safe MCP server (sam-david/pg-redact-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.