hail

Official

by hail-hq

Overview Schema Source Related Servers Discussions Admin

Python

Hybrid

List emails

list_emails

Read-onlyIdempotent

List emails in your organization, newest first.

Instructions

List emails in your organization, newest first.

    Cursor-paginated: pass the previous response's ``next_cursor`` to
    fetch the next page. Two optional server-side filters:

    * ``direction`` — ``outbound`` or ``inbound``. Pass
      ``direction="inbound"`` to read replies and other received mail.
    * ``status`` — one of ``queued``, ``sent``, ``failed``,
      ``bounced``, ``complained``, ``received``.

    Items are trimmed summaries (no message body). Call ``get_email``
    with an item's ``id`` to read the full body.

    Example:
        list_emails(direction="inbound")

    Returns ``{"items": [...], "next_cursor": <str|None>}`` on success,
    or ``{"error": "<message>"}`` instead.

Input Schema

Name	Required	Description	Default
`limit`	No
`cursor`	No
`status`	No
`direction`	No

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.29.0Oct 21, 2026

TDQS

A4.8/5.0

Behavior5/5

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

With readOnlyHint/idempotentHint already covering the safety profile, the description adds what the annotations cannot: items are trimmed summaries without message bodies, responses are cursor-paginated via next_cursor, and errors come back as {"error": ...} rather than throwing. That is meaningful behavioral context beyond structured fields.

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?

Front-loaded with the core statement, then pagination, then filters as scannable bullets, then the escalation path, then return shape. Every sentence carries distinct information; nothing is restated from the schema or annotations.

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?

Pagination, filter semantics, item granularity, return shape, and the follow-up call are all covered, and an output schema exists for deeper shape detail. The one omission is the `limit` parameter's meaning and maximum, which matters for a list tool with server-side pagination.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description carries the burden and does so for the two ambiguous filters, enumerating accepted values for both direction (outbound/inbound) and status (queued, sent, failed, bounced, complained, received) plus how cursor works. It leaves `limit` (default 50) completely undocumented, so one of four parameters is still unexplained anywhere.

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?

States a specific verb and resource ("List emails in your organization") plus ordering ("newest first"), which is scope detail an agent cannot infer from the name. It is clearly distinguishable from get_email (body retrieval) and list_email_domains among the siblings.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly routes the agent: use this list tool for summaries and "Call ``get_email`` with an item's ``id`` to read the full body." It also names the concrete scenario for the inbound filter ("read replies and other received mail") and provides an example call.

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