List Mail Attachments

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

With no annotations, the description carries the full burden. It discloses a behavioral trait (requires delegated Mail.Read) and implies a read-only metadata operation, which is helpful. It could further clarify that it does not return file content, but 'metadata' sufficiently implies this.

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 short sentences efficiently convey purpose and permission. The Chinese intent line adds practical multilingual usage hints without notable bloat, keeping the description appropriately sized.

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 single-parameter metadata listing, the description covers the operation, permission, and intent triggers. It omits specifics about returned fields, but this is acceptable given no output schema and the simplicity of the tool.

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 fully describes the only parameter (messageId as 'Message ID'), providing 100% coverage. The description adds no additional parameter semantics beyond the context of 'for a message', so baseline 3 is appropriate.

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 attachment metadata for a message', using a specific verb and resource. It distinguishes from siblings like mail_get_attachment by specifying 'metadata' rather than content, making the tool's 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 provides clear context by stating the permission requirement and including Chinese intent examples that map to typical user requests. However, it does not explicitly name alternatives or exclusions compared to sibling tools like mail_get_attachment.

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