Trello MCP Server

assign_member_to_card

Assign a specific team member to a card on Trello to clearly delegate tasks and track responsibility.

Instructions

Assign a member to a specific card

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>",
      "memberId": "<memberId>"
    },
    "name": "assign_member_to_card"
  }
}

Input Schema

Name	Required	Description
`boardId`	No	ID of the Trello board (uses default if not provided)
`cardId`	Yes	ID of the card to assign the member to
`memberId`	Yes	ID of the member to assign to the card

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.4May 30, 2026

TDQS

B3.2/5.0

Behavior2/5

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

No annotations provided, and the description does not disclose behavioral traits such as failure conditions, success criteria, or side effects (e.g., notifications).

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?

Single sentence with no redundant information. Efficiently communicates the core action.

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?

With no output schema and no annotations, the description is too brief. It omits important context such as return values, error handling, and required prerequisites.

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%; each parameter already has a clear description. The tool description adds no additional meaning beyond the schema.

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?

Description clearly states the action (assign), the resource (member to card), and is specific. It distinguishes from sibling tools like remove_member_from_card.

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

Usage Guidelines2/5

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

No guidance on when to use or not use this tool versus alternatives. No prerequisites or context about required preconditions (e.g., member must be on the board) are mentioned.

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