mail_list_messages

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

With no annotations provided, the description carries the full burden. It discloses that results are envelope-only by default and supports sort/cursor/snippet, but lacks details on authentication, rate limits, or what 'envelope' information includes. Adequate but not comprehensive.

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 a single sentence, perfectly front-loaded with the primary action ('List recent messages in a folder'), followed by key options. Every word earns its place with no 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?

Given 6 parameters, one required, and no output schema, the description is adequate but misses important details like pagination behavior (cursor usage), the definition of 'envelope', and snippet format. It covers the basics but leaves gaps for new users.

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 has 100% coverage, so baseline is 3. The description adds no additional meaning beyond what each parameter's schema description already provides (e.g., default values, enum). The phrase 'envelope only by default' is not directly tied to any parameter.

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 clearly states 'List recent messages in a folder' with a specific verb and resource, and distinguishes itself from siblings like `mail_get_message` by defaulting to envelope-only. It mentions supported features (sort/cursor/snippet), making its purpose unambiguous.

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 does not provide any guidance on when to use this tool versus alternatives such as `mail_search` or `mail_list_unread`. There is no explicit context about prerequisites or scenarios where this tool is preferred.

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