mail_list_attachments

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

The description explains it lists metadata and does not export, implying a read-only operation. With no annotations, it carries the burden of transparency, but it lacks explicit mention of being non-destructive or requiring any permissions.

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 concise sentences with no wasted words. It front-loads the purpose and includes a clear limitation.

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 list tool with no output schema, the description explains the input and operation but omits details about the return format (e.g., what metadata fields are returned) and pagination, leaving some ambiguity.

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 100% with both parameters described. The tool's description adds only context ('one downloaded message') but no additional semantic meaning beyond the schema descriptions.

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 it lists attachment metadata for one downloaded message and explicitly says it does not export content. This distinguishes it from sibling tools like mail_read_message (message content) and mail_search_messages (searching).

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 specifies the tool is for a single downloaded message, giving clear context. However, it does not provide when-not-to-use scenarios or reference alternative tools for different needs, such as exporting attachments.

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