Trello MCP Server

Get Custom Field Options

get_custom_field_options

Fetch the valid dropdown options from a list-type custom field in Trello. Use this to populate selection menus or verify that a value is among the allowed choices.

Instructions

Get the dropdown options for a list-type custom field. 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": {
      "customFieldId": "<customFieldId>"
    },
    "name": "get_custom_field_options"
  }
}

Input Schema

Name	Required	Description	Default
`customFieldId`	Yes	The ID of the custom field (must be type 'list')

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.2.0Sep 6, 2026

TDQS

A4/5.0

Behavior3/5

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

With no annotations provided, the description carries the full burden. It clearly signals a non-mutating read operation via 'Get' and discloses the plan requirement. It does not describe edge-case behavior such as what happens when the field is not of type 'list' or how options are returned, but for a simple getter this is a reasonable level of transparency.

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 a single, dense sentence that front-loads the core purpose and includes the essential licensing constraint. There is no filler or redundant restatement of the title.

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 simple one-parameter read tool with no output schema, the description covers the essential facts: what it retrieves, the field type, and the license requirement. It could mention the shape of the returned options, but this is not critical for selecting and invoking the tool correctly.

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% and the single parameter is fully documented in the schema. The description adds no additional parameter-level meaning beyond what the schema already states, so the baseline of 3 is appropriate.

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 names a specific verb ('Get') and resource ('dropdown options for a list-type custom field'), making the tool's function unmistakable. It clearly distinguishes this from sibling tools like get_custom_field or get_card_custom_fields without needing to inspect schemas.

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 description conveys a clear usage context: retrieving dropdown options for list-type custom fields. It also adds a meaningful prerequisite (Trello Premium or Enterprise). It does not explicitly mention alternatives or when not to use it, but the context is unambiguous enough for an agent to route correctly.

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

Deploy Server