list_messagesRetrieve messages already delivered to a disposable inbox, newest first, to check for received emails and verification codes without waiting for new arrivals.
List the messages currently in an inbox, newest first. Use this to see what has already arrived, rather than waiting for something new.
| Name | Required | Description | Default |
|---|---|---|---|
| address | Yes | The inbox address. |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. It does disclose that the tool is non-blocking (it lists messages already arrived rather than waiting) and that results are newest first. However, it does not describe what the response contains, whether messages are returned as summaries or full content, or whether any side effects occur.
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?
The description is two sentences with no wasted wording. The core action and ordering are in the first sentence, and the usage distinction is in the second, making it easy to scan and understand.
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?
For a simple tool with one required parameter, the description is largely complete: it explains what the tool does, the ordering, and when to use it. The lack of an output schema could make response-shape details useful, but they are not necessary for selecting or invoking this tool correctly.
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?
The schema already fully documents the single parameter 'address' as 'The inbox address.' The description adds only that the tool operates on an inbox, which is implied by the title and schema. This meets the baseline but adds no extra parameter semantics.
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?
The description states a specific verb ('List'), a specific resource ('messages in an inbox'), and adds scope ('currently') and ordering ('newest first'). This clearly distinguishes the tool from siblings like read_message, which reads a single message, and wait_for_email, which waits for new arrivals.
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?
The description explicitly says to use this tool 'to see what has already arrived, rather than waiting for something new,' which gives clear guidance relative to wait_for_email. It does not explicitly mention alternatives like read_message or delete_inbox, but the context makes the main distinction clear.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.