Retrieve received email messages, newest first, with filters for unread status and date, including pagination; only mail from allowed senders appears.
List received messages (newest first). Only mail from allowed senders is visible.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | ||
| since | No | Only messages received at or after this date (YYYY-MM-DD) or date-time | |
| cursor | No | next_cursor from a previous call | |
| unread | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden and does disclose two useful traits: default ordering (newest first) and a visibility restriction (only mail from allowed senders). It omits pagination behavior, auth/scope requirements, and what happens when the sender filter excludes everything.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two tight sentences, front-loaded with the core action and followed by the key constraint. No padding or redundancy.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Covers the essentials for a list tool (what, order, visibility), but with no annotations, no output schema, and two undocumented parameters, the agent lacks guidance on pagination via cursor and the unread filter. Adequate but with clear gaps.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is only 50%: 'limit' and 'unread' carry no schema description, and the description adds nothing about any parameter. The ordering note does not map to a declared sort parameter, so the ambiguity around limit and unread is left unaddressed.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb and resource ("List received messages") and adds ordering ("newest first"), which distinguishes it from read_message and list_events. However, it does not name or contrast with siblings explicitly, so differentiation is inferable rather than stated.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No when-to-use guidance and no alternatives named (e.g., read_message for a single message). The only conditional content is the visibility constraint, which is a behavioral fact rather than usage routing. An agent must infer usage entirely.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.