Mailchimp MCP Server

set_campaign_content

Set the content of a Mailchimp campaign by providing custom HTML, plain text, or a template ID. Required for sending campaigns.

Instructions

Set campaign content. Provide html for custom content, or template_id to use a template.

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": {
      "campaign_id": "<campaign_id>"
    },
    "name": "set_campaign_content"
  }
}

Input Schema

Name	Required	Description	Default
`campaign_id`	Yes
`html`	No
`plain_text`	No
`template_id`	No

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedMar 21, 2026

TDQS

A3.5/5.0

Behavior2/5

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

No annotations are provided, so the description bears full responsibility. It only states the tool sets content, but omits behavioral details such as whether existing content is overwritten, required permissions, rate limits, or side effects. This is insufficient for an agent to understand the tool's full impact.

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 two sentences with no extraneous information. The first sentence defines the purpose, and the second details usage options. It is appropriately sized and front-loaded.

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?

Given the number of parameters, lack of annotations, and presence of an output schema, the description provides the core function but lacks completeness. It does not mention return values, error handling, or whether the tool overwrites or merges content. For a mutation tool, more context is needed.

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 has 4 parameters with 0% description coverage. The description adds meaning by indicating that html and template_id are the two modes for content, but does not address the plain_text parameter. This adds some value but leaves ambiguity about plain_text's role.

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 clearly states the verb 'Set' and the resource 'campaign content', and distinguishes between two usage modes: providing HTML for custom content or using a template ID. This clearly differentiates from sibling tools like get_campaign_content or update_campaign.

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

Usage Guidelines3/5

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

The description explains the two ways to provide content (html or template_id), implying when to use each. However, it does not provide explicit guidance on when not to use this tool or contrast it with alternatives like update_campaign, which may also modify campaign content.

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

Deploy Server