addComment · Trello MCP Server MCP: Risk & Policy

WHAT IT DOES

What addComment does on Trello MCP Server

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

WHY IT NEEDS A POLICY

Why addComment needs a policy

Adding a comment creates new content on a Trello card but is reversible (comments can be deleted) and has no side effects beyond the comment itself. This is a standard Write operation. Severity is low because comments are non-critical metadata with minimal blast radius—misuse would result in unwanted notes but not data loss or financial impact.

From the tool's definition Tool name 'addComment' and description 'Add a comment to a Trello card. Use this to add notes, updates, or discussions to cards' clearly indicate creation of new comment data on a card.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

addComment Rate-limited

addComment 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": {
    "addComment": {
      "limits": [
        {
          "counter": "addcomment_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 Trello MCP Server, so you can run agents against it safely.

FAQ

Questions about addComment

What does the addComment tool do? +

Add a comment to a Trello card. Use this to add notes, updates, or discussions to cards. It is categorised as a Write tool in the Trello 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 addComment? +

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

What risk level is addComment? +

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

Can I rate-limit addComment? +

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

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

addComment is provided by the Trello MCP Server MCP server (semblancelabs/trello-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.