Fastmail MCP Server

archive_email

Archive single or multiple emails to the Archive mailbox in one step. Clears inbox of processed messages.

Instructions

Move one or more emails to the Archive mailbox. A convenient one-step operation for archiving emails you've dealt with.

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": {
      "emailIds": "<emailIds>"
    },
    "name": "archive_email"
  }
}

Input Schema

Name	Required	Description	Default
`emailIds`	Yes	A single email ID or array of email IDs to archive

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.3.0Aug 2, 2026

TDQS

A4/5.0

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. It clearly states the core behavior (move to Archive mailbox) but does not disclose potential side effects such as whether read flags change, whether emails remain searchable, whether the action is reversible, or what permissions are required. This is typical for a simple mutation but leaves some uncertainty.

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?

Two concise, front-loaded sentences with no filler. Every phrase adds value: the first states the action, the second clarifies the typical use case.

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 single-parameter tool with no output schema and no annotation, the description is nearly complete. It identifies the target mailbox and the scenario for use. It could be slightly more complete by noting whether the archive operation is reversible or whether it affects read state, but the core tool behavior is sufficiently clear.

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?

Schema coverage is 100% and there is only one parameter (emailIds). The description's phrase 'one or more emails' matches the schema's anyOf string/array definition but adds no new semantic information about the parameter beyond what the schema already provides.

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 opens with a clear, specific verb+resource: 'Move one or more emails to the Archive mailbox.' This precisely distinguishes it from sibling tools like move_email (generic move) and delete_email (destructive action). The added phrase 'archiving emails you've dealt with' reinforces the intended use case.

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?

It states a clear context: archive emails that have been dealt with, describing it as a 'convenient one-step operation.' However, it does not explicitly mention when to prefer this over move_email or delete_email, nor does it state any exclusions or prerequisites.

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