Trello MCP

trello_add_comment

Add comments to Trello cards to share notes, updates, or discussion. Provide the card ID and comment text to append the message instantly.

Instructions

Add a comment to a Trello card. Use this to add notes, updates, or discussions to cards.

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": {
      "apiKey": "<apiKey>",
      "token": "<token>",
      "cardId": "<cardId>",
      "text": "<text>"
    },
    "name": "trello_add_comment"
  }
}

Input Schema

Name	Required	Description
`text`	Yes	Text content of the comment
`token`	Yes	Trello API token (automatically provided by Claude.app from your stored credentials)
`apiKey`	Yes	Trello API key (automatically provided by Claude.app from your stored credentials)
`cardId`	Yes	ID of the card to add comment to (you can get this from board details or searches)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Aug 9, 2026

TDQS

A3.8/5.0

Behavior3/5

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

With no annotations provided, the description must carry the burden of behavioral disclosure. It clearly indicates a write operation ('Add'), which lets the agent know the tool mutates data. However, it does not mention permissions, side effects, or response behavior, though for a simple 'add comment' operation these may be less critical.

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

Conciseness5/5

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

The description is exactly two sentences, with the first stating the action and the second offering usage context. There is zero redundancy or extraneous information, making it highly concise and well-structured.

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

Completeness4/5

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

This is a relatively simple tool with four parameters fully described in the schema and no output schema. The description sufficiently covers purpose and usage context. It does not explain return values, but that is not required given the simplicity of the action and the absence of an output schema.

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?

The schema description coverage is 100%, so the schema already documents all four parameters. The description adds no additional parameter-level detail beyond what the schema provides, which is why the baseline score of 3 is appropriate.

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

Purpose4/5

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

The description clearly states the action: 'Add a comment to a Trello card.' This is a specific verb+resource that is unambiguous. It does not explicitly differentiate from sibling tools like update_card or create_card, but the action is distinct enough that no confusion should arise.

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

Usage Guidelines4/5

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

The second sentence, 'Use this to add notes, updates, or discussions to cards,' provides clear context for when to use the tool. It does not mention alternatives or exclusions, but it gives practical guidance on appropriate use cases, which is more than many tool descriptions offer.

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