Apple Mail MCP Server

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reply

Compose a response to an existing email, auto-quoting the original, and send it or save as a draft. Allows setting CC recipients, account, and mailbox.

Instructions

Reply to an existing message.

Convenience wrapper over create_draft with seed=reply.

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": {
      "reply_to": "<reply_to>"
    },
    "name": "reply"
  }
}

Input Schema

Name	Required	Description
`cc`	No	CC recipients (None keeps auto-derived; [] clears).
`body`	No	Reply body. Empty keeps Mail's auto-quoted original.
`reply_to`	Yes	Id of the message to reply to (numeric Mail.app id or RFC 5322 Message-ID from search_messages/get_messages).
`send_now`	No	True (default) sends immediately; False saves as draft.
`from_account`	No	Mail.app account name or UUID. None = Mail default.
`seed_mailbox`	No	Folder the original lives in (default INBOX).

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.10.2Aug 22, 2026

TDQS

A3.6/5.0

Behavior3/5

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

The description adds some behavioral context beyond annotations by revealing that the tool is a wrapper over create_draft with seed=reply, clarifying that it creates drafts/reply flow. Annotations already declare readOnly=false and destructive=false, but the description doesn't go into side effects such as immediate sending or reply-all behavior.

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 two short sentences with no filler. It front-loads the core action and then gives a functional relationship to create_draft.

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 a rich parameter schema and an output schema, the description covers the essential behavior and wraps semantics. It misses an explicit distinction from reply_all and its exact sending/draft behavior, though the schema defaults cover the latter.

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 description coverage is 100%, so the baseline is 3 and the description doesn't need to restate parameter meanings. The 'seed=reply' detail gives useful conceptual context, but it doesn't add meaning beyond the schema for individual parameters.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description names the operation with a specific verb and resource ('Reply to an existing message') and reveals its implementation path as a wrapper over create_draft with seed=reply. It does not explicitly differentiate from reply_all or forward, but the 'existing message' target makes the scope reasonably clear.

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 phrase 'Convenience wrapper over create_draft with seed=reply' implies a targeted alternative to create_draft, but there is no explicit statement of when to choose this over reply_all or when a fuller create_draft call is preferable. Usage guidance is present only by implication.

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