mark_emails_as_unread

THE RISK

Medium Risk

Why mark_emails_as_unread needs a policy

This tool modifies email attributes (read/unread status) but does not create, delete, or execute external operations. The effect is reversible—emails can be marked as read again. While it affects all emails in scope, the blast radius is limited to metadata changes without data loss or financial impact. Classified as Write rather than Read because it performs state mutation, not just retrieval.

From the tool's definition Tool description states 'Mark all emails as unread', which is a state modification operation that changes email metadata. The sibling tool 'mark_emails_as_read' reinforces this pattern of email state manipulation.

Documented attack patterns abuse exactly the kind of access mark_emails_as_unread gives an agent:

POLICY

How to control mark_emails_as_unread

PolicyLayer is an MCP gateway — it sits between your AI agents and Gmail, and nothing reaches the server without passing your rules. This is the rule we recommend for mark_emails_as_unread:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "mark_emails_as_unread": {
      "limits": [
        {
          "counter": "mark_emails_as_unread_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

mark_emails_as_unread 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.

Create a free account and register Gmail — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Gmail tools

Destructive delete_label Delete a single label from gmail Destructive trash_email Thrash an email. Destructive trash_emails Thrash a list of emails. Write add_labels Assign all emails sent with the labels. Write create_label create_label Write mark_emails_as_read Mark all emails as read. Write update_label update_label Read get_all_emails_ids_by_query get_all_emails_ids_by_query

All 12 Gmail tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about mark_emails_as_unread

What does the mark_emails_as_unread tool do? +

Mark all emails as unread. It is categorised as a Write tool in the 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 mark_emails_as_unread? +

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

What risk level is mark_emails_as_unread? +

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

Can I rate-limit mark_emails_as_unread? +

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

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

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

Enforce policy on every Gmail tool call.

Start from Gmail, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →