Trello MCP Server

Delete Custom Field

delete_custom_field

Delete a custom field definition and remove its values from all cards. Requires Trello Premium or Enterprise.

Instructions

Delete a custom field definition and all its values from every card. 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": "delete_custom_field"
  }
}

Input Schema

Name	Required	Description	Default
`customFieldId`	Yes	The ID of the custom field to delete

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.2.0Sep 6, 2026

TDQS

A4.2/5.0

Behavior4/5

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does well by stating that deletion cascades to 'all its values from every card' and adds the Trello Premium/Enterprise requirement. It does not explicitly mention irreversibility or permission requirements, but the destructive cascade is clearly disclosed.

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 concise sentences with no filler. The action and its cascading effect are front-loaded, and the licensing requirement is added as a second sentence. Every word earns its place.

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 one-parameter destructive operation with no output schema, the description covers the essential context: what is deleted, the scope of impact, and the plan requirement. It could be slightly richer by noting that the operation is irreversible, but the current description is sufficient for an agent to understand the tool's behavior.

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 the single parameter customFieldId is already fully documented as 'The ID of the custom field to delete.' The description adds no further parameter-level nuance, which is acceptable given the complete schema coverage.

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 ('delete'), a precise resource ('custom field definition'), and a consequential scope ('and all its values from every card'). This clearly distinguishes the tool from siblings like get_custom_field, create_custom_field, and update_custom_field_item 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 implies the usage context: use this when you need to permanently remove a custom field definition across all cards. It does not explicitly name alternatives or exclusion conditions, but the destructive scope and licensing requirement provide clear situational context.

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

Deploy Server