Get Mail Attachment

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

No annotations are provided, but the description compensates with key behavioral details: raw=true returns base64 bytes, a 10MB limit, and a delegated Mail.Read permission requirement. It does not explain the default (raw=false) return format, which is a transparency gap.

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 concise sentences plus a Chinese intent list, immediately stating the core purpose. Every sentence adds value—usage, size limit, permission, and multilingual support—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?

The description covers the essential operation, size limit, and permission, but lacks an output schema and does not clarify the default return format or how to obtain attachmentId from mail_list_attachments. This leaves the tool incomplete for an agent to fully anticipate results.

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 provides descriptions for all three parameters (100% coverage), so the baseline is 3. The description reinforces raw=true base64 behavior and adds the 10MB limit, but adds nothing beyond the schema for messageId/attachmentId.

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 opens with 'Read one mail attachment,' which is a specific verb (read) and resource (mail attachment), and it distinguishes from sibling mail_list_attachments by focusing on a single attachment's content. The inclusion of 'one' clarifies scope.

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 implies usage for fetching attachment content but does not explicitly contrast with alternatives like mail_list_attachments (listing) or mail_get_message (message). No when-not-to-use or alternative tool is named, so guidance is only implicit.

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