update_comment · Google MCP: Risk & Policy

WHAT IT DOES

What update_comment does on Google

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

WHY IT NEEDS A POLICY

Why update_comment needs a policy

The tool modifies comments (a reversible change) on Drive files. Comments are typically secondary metadata and cannot cause data loss or execute code. While the tool creates side effects (changes to the file's comment thread), the impact is limited to comment text editing, making it a Write-category risk with low severity.

From the tool's definition Tool name 'update_comment' and description 'Edit a comment on a Google Drive file' indicate modification of existing metadata/annotations rather than core document content or data deletion.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_comment Rate-limited

update_comment 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_comment": {
      "limits": [
        {
          "counter": "update_comment_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 Google, so you can run agents against it safely.

FAQ

Questions about update_comment

What does the update_comment tool do? +

Edit a comment on a Google Drive file. It is categorised as a Write tool in the Google 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_comment? +

Register the Google MCP server in PolicyLayer and add a rule for update_comment: 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 Google. Nothing to install.

What risk level is update_comment? +

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

Can I rate-limit update_comment? +

Yes. Add a rate_limit block to the update_comment 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_comment completely? +

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

update_comment is provided by the Google MCP server (ztgluis/google-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.