Gmail MCP Server

gmail_send_message_with_attachment

Send an email with a file attachment through Gmail. Specify recipient, subject, body, and file path, with optional CC.

Instructions

Send Gmail message with attachment.

Args: to: Recipient email address subject: Email subject body: Email body content file_path: Path to file to attach cc: CC recipients (comma-separated)

Returns: Dictionary with send result

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": {
      "to": "<to>",
      "subject": "<subject>",
      "body": "<body>",
      "file_path": "<file_path>"
    },
    "name": "gmail_send_message_with_attachment"
  }
}

Input Schema

Name	Required	Description	Default
`cc`	No
`to`	Yes
`body`	Yes
`subject`	Yes
`file_path`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jul 30, 2026

TDQS

B3.3/5.0

Behavior2/5

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

With no annotations provided, the description must disclose behavioral traits. It only states the action and arguments, lacking details on authentication, attachment size limits, error handling, or side effects. This is insufficient for an AI agent to understand the full behavior.

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 concise with a front-loaded purpose sentence followed by a brief argument list. Every sentence is necessary, though the argument list could be integrated more succinctly. Still, it is well-structured for quick comprehension.

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 that sends emails with attachments, the description is incomplete. It lacks details on return value format (only 'Dictionary with send result'), attachment handling specifics, or potential constraints (e.g., file size limits, supported file types). Given no output schema and 0% parameter schema coverage, 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?

Given 0% schema description coverage, the tool description adds basic semantics for each parameter (e.g., 'to: Recipient email address'). However, it omits validation rules, formatting requirements, or edge cases, providing only minimal meaning beyond the parameter names.

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 'Send Gmail message with attachment,' specifying the verb (send) and resource (Gmail message) with a distinguishing feature (attachment). This effectively differentiates it from the sibling tool 'gmail_send_message' which presumably sends without attachment.

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 implies when to use the tool (when an attachment is needed) but does not explicitly state conditions or exclusions compared to alternatives like gmail_send_message. No guidance on prerequisites or context is provided.

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

Deploy Server