Medium Risk

create_card

Create a new card in a Trello list. Use this to add tasks, ideas, or items to your workflow.

How to control create_card ↓

What create_card does on Trello Desktop MCP

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

Medium Risk

Why create_card needs a policy

The tool creates new Trello cards, which is a write operation that modifies the state of a board by adding data. This is reversible (cards can be deleted), distinguishing it from destructive operations. The severity is medium because misuse could clutter boards or create unwanted tasks, but the blast radius is limited to the specific Trello workspace and the action is easily remediated.

From the tool's definition Tool description states 'Create a new card in a Trello list' — this creates new data objects that are reversible (cards can be deleted or modified after creation).

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

How to control create_card

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

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "create_card": {
      "limits": [
        {
          "counter": "create_card_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

create_card 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.

  1. Create a free account and register Trello Desktop MCP — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
LIMIT THIS TOOL →

Free to start. No card required.

Related tools and policies

Go deeper

Questions about create_card

What does the create_card tool do? +

Create a new card in a Trello list. Use this to add tasks, ideas, or items to your workflow. It is categorised as a Write tool in the Trello Desktop MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_card? +

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

What risk level is create_card? +

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

Can I rate-limit create_card? +

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

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

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

Enforce policy on every Trello Desktop MCP tool call.

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

Free to start. No card required.

19 Trello Desktop MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

// GET IN TOUCH

Have a question or want to learn more? Send us a message.

Message sent.

We'll get back to you soon.