gmail_thread_mark_read · Mcp Gmail MCP: Risk & Policy

WHAT IT DOES

What gmail_thread_mark_read does on Mcp Gmail

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

WHY IT NEEDS A POLICY

Why gmail_thread_mark_read needs a policy

This tool modifies message metadata (read/unread status) across a thread, which is a reversible write operation. While it affects multiple messages, the change is non-destructive and can be undone by marking messages unread again. It does not delete data, execute code, or create financial obligations.

From the tool's definition Tool description explicitly states 'Mark every message in a thread as read (remove the' - indicating it modifies message state by removing the unread flag. The incomplete description confirms it performs state modification rather than retrieval.

Risk signalsBulk/mass operation — affects multiple targets

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

gmail_thread_mark_read Rate-limited

gmail_thread_mark_read 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": {
    "gmail_thread_mark_read": {
      "limits": [
        {
          "counter": "gmail_thread_mark_read_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 Mcp Gmail, so you can run agents against it safely.

FAQ

Questions about gmail_thread_mark_read

What does the gmail_thread_mark_read tool do? +

Mark every message in a thread as read (remove the. It is categorised as a Write tool in the Mcp Gmail MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on gmail_thread_mark_read? +

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

What risk level is gmail_thread_mark_read? +

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

Can I rate-limit gmail_thread_mark_read? +

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

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

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