addLabelToCard · Trello MCP Server MCP: Risk & Policy

WHAT IT DOES

What addLabelToCard does on Trello MCP Server

AI agents use addLabelToCard 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 addLabelToCard needs a policy

This tool creates or modifies data (adds a label to a card) in a reversible manner—labels can be removed or changed without destructive consequences. It does not delete, execute code, trigger external operations, or move money. The blast radius of misuse is minimal, affecting only card organization metadata.

From the tool's definition Tool name 'addLabelToCard' and description 'Add a label to a Trello card for categorization' indicates a modification operation that adds metadata to a card.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

addLabelToCard Rate-limited

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

FAQ

Questions about addLabelToCard

What does the addLabelToCard tool do? +

Add a label to a Trello card for categorization. Labels help organize cards by type, priority, or category. 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 addLabelToCard? +

Register the Trello MCP Server MCP server in PolicyLayer and add a rule for addLabelToCard: 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 addLabelToCard? +

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

Can I rate-limit addLabelToCard? +

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

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

addLabelToCard 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.