mail-mcp

by tecnologicachile

Overview Schema Source Related Servers Discussions Admin

Rust

Local

imap_search_messages

Search messages with cursor pagination

Instructions

Search messages with cursor pagination

Input Schema

Name	Required	Description	Default
`to`	No	Filter by To header
`from`	No	Filter by From header
`limit`	No	Maximum messages to return (1..50, default 10)
`query`	No	Full-text search query
`cursor`	No	Pagination cursor from previous search result
`mailbox`	Yes	Mailbox to search (e.g., `INBOX`, `Sent`, `Archive`)
`subject`	No	Filter by Subject header
`end_date`	No	Filter to messages before this date (YYYY-MM-DD)
`last_days`	No	Filter to messages from last N days
`account_id`	No	Account identifier (defaults to `"default"`)	default
`start_date`	No	Filter to messages on or after this date (YYYY-MM-DD)
`unread_only`	No	Filter to unread messages only
`include_snippet`	No	Include subject snippet in results
`snippet_max_chars`	No	Maximum snippet length (50..500, requires `include_snippet=true`)
`thread_message_id`	No	Find a conversation by its RFC 5322 Message-ID (angle brackets optional): matches the message itself and every message whose In-Reply-To or References header carries it, i.e. the replies in this mailbox

Output Schema

Name	Required	Description
`data`	Yes	Tool-specific data payload
`meta`	Yes	Execution metadata (timestamp, duration)
`summary`	Yes	Human-readable summary of the operation outcome

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv0.4.17Oct 14, 2026

addedInput schema / properties / thread_message_id

Added value: +{
+  "description": "Find a conversation by its RFC 5322 Message-ID (angle brackets optional):\nmatches the message itself and every message whose In-Reply-To or\nReferences header carries it, i.e. the replies in this mailbox",
+  "nullable": true,
+  "type": "string"
+}

First observedv0.4.12Sep 9, 2026

TDQS

C2.9/5.0

Behavior2/5

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

No annotations are provided, so the description carries the full behavioral burden. It mentions cursor pagination, which is genuinely useful context, but says nothing about read-only semantics, result limits, how cursors are threaded across calls, or typical latency/cost.

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?

A single front-loaded sentence with zero wasted words. It is arguably too terse for a 15-parameter search tool, but nothing in it is filler.

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

Completeness3/5

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

An output schema exists, so return format need not be explained, and the schema fully documents parameters. Still, for a multi-criteria search tool with four sibling search variants, the description omits filtering capability and cursor flow detail that would help an agent invoke it correctly.

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 all 15 parameters (from/to/subject/query/date filters, limit, cursor, snippet options) are already documented in the schema. The description adds no parameter meaning beyond that, which lands at the baseline 3.

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?

States a clear verb+resource ('Search messages'), which an agent can understand immediately. However, it does nothing to distinguish itself from siblings like ews_search_messages, imap_search_all_mailboxes, imap_search_and_delete, and imap_search_and_move, so scope boundaries are left to inference.

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?

The description gives no when-to-use guidance, no prerequisites, and no mention of when a sibling search tool is preferable. It only notes the pagination style, which is a property of the tool rather than usage direction.

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