add_thread_message · Yocoolab MCP: Risk & Policy

WHAT IT DOES

What add_thread_message does on Yocoolab

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

WHY IT NEEDS A POLICY

Why add_thread_message needs a policy

This tool creates new content (messages) in an existing feedback thread, making it a Write operation. It does not execute code, delete data, or move money. Severity is medium because posting messages to design feedback threads could allow an AI agent to spam threads, post misleading information, or impersonate feedback, but the impact is limited to a development/design collaboration context and can be undone by…

From the tool's definition Tool description states 'Add a message to a feedback thread' — this creates new data (message) in a feedback thread. The tool modifies thread state by appending a message, which is a reversible write operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_thread_message Rate-limited

add_thread_message 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": {
    "add_thread_message": {
      "limits": [
        {
          "counter": "add_thread_message_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 Yocoolab, so you can run agents against it safely.

FAQ

Questions about add_thread_message

What does the add_thread_message tool do? +

Add a message to a feedback thread without changing its status. Use this to post updates like preview URLs, implementation notes, or questions back to the thread. It is categorised as a Write tool in the Yocoolab MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_thread_message? +

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

What risk level is add_thread_message? +

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

Can I rate-limit add_thread_message? +

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

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

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