Atlassian Trello MCP Server

trello_get_card_attachments

Retrieve all attachments, including files and links, for a specified Trello card by providing its ID or URL.

Instructions

Get all attachments (files, links) for a specific Trello card.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "cardId": "<cardId>"
    },
    "name": "trello_get_card_attachments"
  }
}

Input Schema

Name	Required	Description
`apiKey`	No	Trello API key (optional if TRELLO_API_KEY env var is set)
`token`	No	Trello API token (optional if TRELLO_TOKEN env var is set)
`cardId`	Yes	ID or URL of the card (e.g. "abc123" or "https://trello.com/c/abc123/1-title")
`fields`	No	Optional: specific fields to include (e.g., ["name", "url", "mimeType", "date"])

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.2.1May 8, 2026

TDQS

B3.3/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations are absent, so the description must provide behavioral clues. It only states the purpose but does not disclose that it is read-only, how authentication works (though apiKey/token are in schema), or any other behavioral details such as whether it returns both files and links or how the 'fields' parameter affects output.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, clear sentence that efficiently conveys the tool's purpose. It is front-loaded with the action, but could be slightly more informative without losing conciseness.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the lack of output schema and the complexity of parameters (especially the 'fields' array), the description does not sufficiently prepare an agent. It fails to explain what constitutes an attachment in Trello or the expected return format, which is necessary for effective invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so baseline is 3. The description adds no additional meaning beyond the schema descriptions, not even clarifying the 'fields' parameter's impact on the result.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action ('Get all attachments') and the target resource ('for a specific Trello card'). It distinguishes itself from siblings like 'trello_create_card_attachment' and 'trello_delete_card_attachment' by using 'get' and 'all'.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No explicit guidance on when to use this tool versus alternatives like 'get_card' or 'trello_get_card_attachment'. The context is implied but not stated, giving only an implied usage scenario.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server