Trello MCP Server

Get Board Custom Fields

get_board_custom_fields

Retrieve all custom field definitions on a Trello board to see available fields and their configurations. Requires Premium or Enterprise.

Instructions

Get all custom field definitions on a board. Requires Trello Premium or Enterprise.

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": {
      "boardId": "<boardId>"
    },
    "name": "get_board_custom_fields"
  }
}

Input Schema

Name	Required	Description	Default
`boardId`	Yes	The ID of the board

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.2.0Sep 6, 2026

TDQS

A3.8/5.0

Behavior3/5

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

With no annotations, the description carries the behavioral disclosure burden. It usefully states the Trello Premium or Enterprise requirement and clarifies that the result is definitions rather than values. It does not cover response format, pagination, or error behavior, but the read-only nature is strongly implied by 'get'.

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?

Two short sentences with no filler. The action is front-loaded and the licensing prerequisite is stated as an important follow-up. Every phrase contributes useful information.

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?

For a single-parameter read operation with no output schema, the description covers the essential purpose and the key constraint (paid plan requirement). It could have added a note about the return shape or the card-level alternative, but nothing critical is missing for selecting and invoking the tool.

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 only parameter, boardId, is already fully documented in the schema with 100% coverage. The description adds no extra semantic detail about the parameter beyond reinforcing that the operation is board-scoped. The baseline of 3 applies because the schema handles the parameter documentation.

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 uses a specific verb ('Get') and a precise resource ('all custom field definitions on a board'). It distinguishes this tool from sibling tools like get_custom_field and get_card_custom_fields by emphasizing the board-level and definition-focused scope.

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 implies the intended use: retrieve all custom field definitions at board level. However, it gives no explicit when-to-use guidance and does not mention alternatives for single custom fields or card-level custom field values.

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

Deploy Server