Skip to main content
Glama
damientilman

Mailchimp MCP

upload_file

Upload base64-encoded images and files to Mailchimp's File Manager for embedding in campaigns and templates. Returns a hosted URL.

Instructions

Upload a new image or file to the File Manager (base64-encoded).

Enables programmatic image hosting for campaign and template content: upload here, then reference the returned full_size_url in your HTML. Use list_file_folders to target a folder, list_files to browse existing files, and delete_file to remove one.

Authenticated via API key. Max 10 concurrent requests. Respects read-only and dry-run modes.

Args: name: File name including extension (e.g. 'hero.png'). Shown in the File Manager. file_data: The file content, base64-encoded (not a URL or raw bytes). folder_id: Optional folder ID (from list_file_folders) to upload into. Omit for the root. account: Optional account name (e.g. 'marketing') configured via MAILCHIMP_API_KEY_. Omit to use the default account. See list_accounts.

Returns: JSON with id (use as file_id), name, type, full_size_url (hosted URL for embedding), thumbnail_url, size, width, height, folder_id, created_at.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
nameYes
accountNo
file_dataYes
folder_idNo

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
resultYes
Behavior5/5

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

Discloses upload behavior, base64 encoding requirement, concurrency limits, authentication, and dry-run/read-only mode compliance, exceeding annotation info (readOnlyHint=false).

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?

Well-structured with overview, Args, Returns; front-loaded with purpose. Slightly verbose but each sentence adds value.

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

Completeness5/5

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

With output schema present, description covers workflow, return fields, and relationships to other tools, making it fully informative for an agent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters5/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Despite 0% schema coverage, description explains all parameters: name (file name), file_data (base64), folder_id (optional from list_file_folders), account (optional), providing clear meaning beyond 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?

The description clearly states the tool uploads a file (image or file) to File Manager using base64 encoding, distinguishing it from sibling tools like delete_file, list_files, etc.

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

Usage Guidelines4/5

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

Explanation of related tools (list_file_folders, list_files, delete_file), authentication, rate limits, and modes (read-only/dry-run). Could mention when not to use but provides good context.

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

Install Server

Other Tools

Latest Blog Posts

MCP directory API

We provide all the information about MCP servers via our MCP API.

curl -X GET 'https://glama.ai/api/mcp/v1/servers/damientilman/mailchimp-mcp-server'

If you have feedback or need assistance with the MCP directory API, please join our Discord server