attach_card_link

Attach a URL to a card. When the URL points to another Trello card (e.g. https://trello.com/c/<shortLink>), Trello renders it as a card-preview chip in the target card

SERVERTrello SOURCE@asapo/trello-mcp-server

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade D, identity unverified Pull the record →

This record as markdown: /tools/asapo-trello-mcp-server/attach-card-link.md

WHAT IT DOES

What attach_card_link does on Trello

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

RISK

Why attach_card_link is rated Medium

An AI agent can call attach_card_link faster than any human can review: one bad instruction and it creates or modifies resources in Trello by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs attach_card_link safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Trello, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For attach_card_link, this is the rule to start with:

attach_card_link Rate-limited

attach_card_link 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": {
    "attach_card_link": {
      "limits": [
        {
          "counter": "attach_card_link_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Trello, apply this rule, and every attach_card_link call is checked against it from then on.

FAQ

Questions about attach_card_link

What does the attach_card_link tool do? +

Attach a URL to a card. When the URL points to another Trello card (e.g. https://trello.com/c/<shortLink>), Trello renders it as a card-preview chip in the target card. It is categorised as a Write tool in the Trello MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on attach_card_link? +

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

What risk level is attach_card_link? +

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

Can I rate-limit attach_card_link? +

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

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

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

KEEP EXPLORING

More on Trello, and thousands of servers like it.

This server

All 23 Trello tools →

Across the catalogue

The MCP Attack Database →

Guides

Govern customer-ops agents →Argument validation →Scoped token →