Mailchimp MCP Server

mailchimp_ecommerce_customers_update

Update e-commerce customer details in Mailchimp by specifying store ID and customer ID, and optionally set first name, last name, or opt-in status.

Instructions

Update a customer

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": {
      "store_id": "<store_id>",
      "customer_id": "<customer_id>"
    },
    "name": "mailchimp_ecommerce_customers_update"
  }
}

Input Schema

Name	Required	Description
`store_id`	Yes	Store ID
`last_name`	No	Updated last name
`first_name`	No	Updated first name
`customer_id`	Yes	Customer ID
`opt_in_status`	No	Updated opt-in status

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Aug 2, 2026

TDQS

C2.7/5.0

Behavior1/5

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

With no annotations, the description carries the full burden of behavioral disclosure. 'Update a customer' reveals only that a mutation occurs, with no information about partial vs. full updates, behavior when the customer does not exist, or what response to expect. This is a significant gap for a mutation tool.

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

Conciseness4/5

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

The description is extremely concise with no wasted words. However, it is under-specified rather than efficiently informative, which slightly reduces the score from a perfect 5.

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?

For a tool with 5 parameters, 2 required, no annotations, and no output schema, the description is insufficient. It fails to mention that store_id and customer_id identify the customer, that other fields are optional updates, or any operational context. The schema fills some gaps, but the description does not adequately support an agent's decision-making.

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 schema descriptions cover 100% of the parameters, so the baseline is 3. The description adds no additional meaning beyond what the schema already provides, so it neither enhances nor hurts parameter understanding.

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 a customer' clearly identifies the verb and resource, but it lacks the 'e-commerce' store context and does not differentiate from sibling tools like mailchimp_members_update. The tool name provides the necessary specificity, but the description itself is generic.

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 is provided on when to use this tool versus alternatives such as mailchimp_ecommerce_customers_add or mailchimp_ecommerce_customers_get, nor are prerequisites like store_id and customer_id explained. The description simply states the action without any contextual direction.

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

Deploy Server