patch_label · Gmail MCP Server MCP: Risk & Policy

WHAT IT DOES

What patch_label does on Gmail MCP Server

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

WHY IT NEEDS A POLICY

Why patch_label needs a policy

This tool modifies Gmail label configurations (name, color, visibility, etc.) but does not delete data or create financial obligations. The blast radius is medium because misconfiguration could affect email organization and filtering, but changes are reversible via additional patch operations.

From the tool's definition patch_label performs a 'partial update' to an existing label, modifying label properties without creating or deleting the label itself. The verb 'patch' indicates a reversible modification operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

patch_label Rate-limited

patch_label 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_label": {
      "limits": [
        {
          "counter": "patch_label_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 Gmail MCP Server, so you can run agents against it safely.

FAQ

Questions about patch_label

What does the patch_label tool do? +

Patch an existing label (partial update). It is categorised as a Write tool in the Gmail 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_label? +

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

What risk level is patch_label? +

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

Can I rate-limit patch_label? +

Yes. Add a rate_limit block to the patch_label 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_label completely? +

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

patch_label is provided by the Gmail MCP Server MCP server (nk900600/gmail-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.