Mailchimp MCP Server

mailchimp_lists_update

Update audience list settings in Mailchimp, including name, contact info, campaign defaults, and permission reminders.

Instructions

Update list settings

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": {
      "list_id": "<list_id>"
    },
    "name": "mailchimp_lists_update"
  }
}

Input Schema

Name	Required	Description
`name`	No	Updated list name
`contact`	No	Updated contact information
`list_id`	Yes	List ID
`campaign_defaults`	No	Updated campaign defaults
`email_type_option`	No	Email type option
`permission_reminder`	No	Updated permission reminder

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Aug 2, 2026

TDQS

C2.8/5.0

Behavior2/5

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

No annotations are provided, so the description must fully disclose behavioral traits. 'Update list settings' only implies mutation; it does not state whether updates are partial (e.g., only provided fields change) or full replacements, what happens to unspecified settings, or whether any permissions are required. This is a critical gap for a mutation tool with no annotation coverage.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness3/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is extremely short, containing no filler, but it is under-specified. It reads as a fragment rather than a complete sentence and lacks crucial context, making it not well-rounded. While it is front-loaded and terse, the brevity sacrifices utility, so it does not reach the 'appropriately sized' standard.

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?

Given that this tool has six parameters, nested objects, and no output schema, the description is far too minimal. It does not explain update semantics (e.g., partial update behavior), return values, or any side effects. The schema covers parameter structure but not behavior, and the description fails to fill that gap, leaving the agent ill-informed for correct 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?

The input schema provides 100% coverage with descriptive texts for all six parameters, including 'Updated list name' and 'Updated contact information'. The tool description adds no additional parameter semantics beyond the schema, so the baseline score of 3 applies. The schema handles parameter meaning adequately.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description 'Update list settings' clearly indicates this tool performs an update operation targeting list configuration. It distinguishes itself from sibling list tools like mailchimp_lists_get, mailchimp_lists_create, and mailchimp_lists_delete, though it does not clarify which specific settings beyond what the schema lists. It is direct and not misleading, but it lacks a fuller explanation of the scope of 'list settings'.

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?

There is no guidance on when to use this tool versus alternatives such as mailchimp_lists_create or mailchimp_lists_update_segment. It does not state that the list must already exist, nor does it suggest any prerequisites. The description leaves the agent without decision-making support for choosing this tool over similar update tools.

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

Deploy Server