Fastmail MCP Server

get_email

Retrieve full email content by ID, including headers, body text, and attachment details.

Instructions

Get the full content of a specific email by its ID, including headers, body text, and attachment info

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": {
      "emailId": "<emailId>"
    },
    "name": "get_email"
  }
}

Input Schema

Name	Required	Description	Default
`emailId`	Yes	The email ID to retrieve

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.3.0Aug 2, 2026

TDQS

A4.2/5.0

Behavior4/5

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

No annotations are provided, so the description carries the full burden. It discloses the scope of the response (headers, body text, attachment info), which is not specified elsewhere. It does not cover error behavior or side effects, but for a simple read operation this is adequate.

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 a single, well-formed sentence that immediately states the verb and object. It is concise and front-loaded, with no wasted words.

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?

With one parameter and no output schema, the description sufficiently communicates what is returned (headers, body text, attachment info). While it doesn't detail the return structure, it covers the key elements one would expect from a 'get email' operation.

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 already provides 100% coverage for the emailId parameter with its description. The tool description simply repeats 'by its ID' without adding format details, source guidance, or clarification of where to find the ID. Baseline 3 is appropriate.

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 action 'Get the full content of a specific email by its ID' and enumerates what is included (headers, body text, attachment info). This distinguishes it from sibling tools like get_email_headers and get_email_attachments, which retrieve only those subsets.

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?

The description implies the use case: retrieve the full email content when you have an email ID. However, it does not explicitly mention alternatives or when not to use it (e.g., if you only need headers, use get_email_headers). The context is clear but lacks explicit exclusions.

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