Trello MCP Server

Add Board Member

add_board_member

Add a member to a Trello board and set their role to admin, normal, or observer to control access and permissions.

Instructions

Add a member to a board with a specified role.

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

Input Schema

Name	Required	Description
`type`	No	Member role on the board (default: normal)
`boardId`	Yes	The ID of the board
`memberId`	Yes	The ID of the member to add

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.2.0Sep 6, 2026

TDQS

B3.3/5.0

Behavior2/5

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

There are no annotations, so the description carries the full behavioral burden. While it clearly indicates a mutation ('Add'), it does not disclose whether the member must already exist, how duplicate additions are handled, permission requirements, or any side effects. The phrase 'specified role' also slightly conflicts with the schema's optional type parameter defaulting to 'normal'.

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 short sentence with the action front-loaded and no wasted words. It is immediately parsable and compact, making it ideal for quick agent consumption.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple three-parameter mutation tool, this is adequate but incomplete. With no annotations and no output schema, it lacks important context such as whether the member must already be a user or organization member, behavior on duplicate membership, and what to expect in the response. These are meaningful gaps for reliable invocation.

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 baseline is 3. The description only reinforces that a role can be specified, which the schema already documents; it adds no meaningful detail about boardId or memberId beyond what the schema provides.

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 'Add' with a clear resource ('member to a board') and adds role detail ('with a specified role'). It unambiguously distinguishes from the sibling add_member_to_card (board vs card) and directly complements remove_board_member.

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?

The description provides no guidance about when to use this tool versus alternatives. It does not mention that card membership uses a different tool, nor does it state prerequisites or exclusions, leaving the agent to infer usage entirely from the name and schema.

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

Deploy Server