patch_secret · Sirr MCP Server MCP: Risk & Policy

WHAT IT DOES

What patch_secret does on Sirr MCP Server

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

WHY IT NEEDS A POLICY

Why patch_secret needs a policy

This tool modifies existing secrets in the vault. While updates are theoretically reversible (via further updates or restore operations), the ability to alter secrets—especially credentials stored in a security vault—represents a high-severity write risk. An agent could corrupt, redirect, or compromise secrets for authentication or authorization purposes.

From the tool's definition Tool description states 'Update an existing secret' which is a reversible modification operation. The mention of 'requires owner key' indicates controlled access but does not change the fundamental nature of the action as a write operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

patch_secret Rate-limited

patch_secret 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": {
    "patch_secret": {
      "limits": [
        {
          "counter": "patch_secret_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 Sirr MCP Server, so you can run agents against it safely.

FAQ

Questions about patch_secret

What does the patch_secret tool do? +

Update an existing secret (requires owner key). It is categorised as a Write tool in the Sirr 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 patch_secret? +

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

What risk level is patch_secret? +

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

Can I rate-limit patch_secret? +

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

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

patch_secret is provided by the Sirr MCP Server MCP server (sirrlock/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.