update_message_labels · AgentMail MCP Server MCP

WHAT IT DOES

What update_message_labels does on AgentMail MCP Server

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

WHY IT NEEDS A POLICY

Why update_message_labels needs a policy

This is a Write operation because it creates or modifies data reversibly. Changing message labels is metadata manipulation that can be undone by relabeling the message again. It does not delete data (excluding Destructive), execute arbitrary code (Execute), or involve financial transactions (Financial).

From the tool's definition The tool 'update_message_labels' modifies metadata on existing messages by adding or removing labels, which is a reversible data modification operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_message_labels Rate-limited

update_message_labels 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_message_labels": {
      "limits": [
        {
          "counter": "update_message_labels_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches AgentMail MCP Server, so you can run agents against it safely.

FAQ

Questions about update_message_labels

What does the update_message_labels tool do? +

Update labels on a message (add new labels and/or remove existing ones). It is categorised as a Write tool in the AgentMail 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 update_message_labels? +

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

What risk level is update_message_labels? +

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

Can I rate-limit update_message_labels? +

Yes. Add a rate_limit block to the update_message_labels 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_message_labels completely? +

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

update_message_labels is provided by the AgentMail MCP Server MCP server (kamath/agentmail-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

// THE FULL RECORD

update_message_labels is one line of AgentMail MCP Server's registry record.

The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.

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