google-workspace-mcp-advanced

get_gmail_attachment_content

Download the content of a specific Gmail attachment by providing the message ID, attachment ID, and user email. Use the returned base64-encoded data to save or process the attachment.

Instructions

Downloads the content of a specific email attachment.

Args: message_id (str): The ID of the Gmail message containing the attachment. attachment_id (str): The ID of the attachment to download. user_google_email (str): The user's Google email address. Required.

Returns: str: Attachment metadata and base64-encoded content that can be decoded and saved.

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": {
      "message_id": "<message_id>",
      "attachment_id": "<attachment_id>",
      "user_google_email": "<user_google_email>"
    },
    "name": "get_gmail_attachment_content"
  }
}

Input Schema

Name	Required	Description	Default
`message_id`	Yes
`attachment_id`	Yes
`user_google_email`	Yes

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.10Jun 2, 2026

TDQS

A3.6/5.0

Behavior3/5

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses that the return value is base64-encoded content that can be decoded and saved, but it does not mention any side effects, access requirements beyond user_google_email, or error conditions. It provides basic behavior but lacks deeper context.

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 concise and well-structured, with a short purpose statement followed by clearly formatted Args and Returns sections. Every sentence provides necessary information without redundant filler.

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

Completeness4/5

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

For a simple 3-parameter read operation, the description covers the essential aspects: what it does, all parameters, and the return format. While it lacks usage guidelines, those are addressed in dimension 2, and the existing output schema reduces the need to detail return values further. Overall, it is nearly complete for its complexity.

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?

Since schema description coverage is 0%, the description is the only source of parameter meaning. It provides brief explanations for all three parameters, such as message_id being 'The ID of the Gmail message containing the attachment'. However, these explanations are largely restatements of the parameter names and do not explain how to obtain the IDs or the expected format, offering only minimal added value over the 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 'Downloads the content of a specific email attachment', which is a specific verb+resource combination. It distinguishes from sibling tools like get_gmail_message_content by explicitly focusing on attachment content rather than message content.

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 get_gmail_messages_content_batch or get_gmail_thread_content. The description implies you need both a message_id and attachment_id, but it does not explain why this tool should be chosen over others for a given scenario.

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

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