Atlassian Trello MCP Server

trello_add_comment

Add a comment to a Trello card for notes, updates, or discussions. Provide card ID and text content.

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

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 to add comment to (e.g. "abc123" or "https://trello.com/c/abc123/1-title")
`text`	Yes	Text content of the comment

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.2.1May 8, 2026

TDQS

B3.2/5.0

Behavior2/5

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

No annotations are provided, so the description carries full burden. It states the operation is adding a comment (write), but does not mention authentication requirements (though covered in schema), rate limits, error conditions, or result behavior. Minimal disclosure.

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 extremely concise: two sentences with no wasted words. It front-loads the core action and then provides usage context. Every sentence earns its place.

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 no output schema, the description should explain what the tool returns (e.g., success confirmation, comment object). It does not. It also fails to mention edge cases (e.g., non-existent card). For a simple tool, it is incomplete.

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 coverage is 100% with descriptions for all parameters. The tool description adds no extra meaning beyond what the schema already provides (e.g., 'cardId' is described in schema as ID or URL; 'text' as text content). 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 verb 'Add' and resource 'comment to a Trello card', and provides use cases ('notes, updates, or discussions'). However, it does not differentiate from sibling tools, though no other tool has the exact same purpose.

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?

The description gives a basic suggestion of when to use the tool ('to add notes, updates, or discussions'), but lacks explicit guidance on when not to use it or alternatives. No contrast with similar tools like 'trello_add_label_to_card'.

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

Deploy Server