Read mail attachment

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

Beyond the readOnlyHint annotation, the description details how each content type is handled (downscaling for images, conversion via pandoc/libreoffice, calendar summary). It also explains error handling for unsupported types.

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 well-structured: a clear one-line purpose, then a detailed but concise explanation of behavior by type, a prerequisite, and parameter descriptions. No wasted words.

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 the complexity of handling multiple attachment types, the description covers all relevant aspects: supported types, processing details, prerequisites, and failure modes. No gaps remain.

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?

Despite 0% schema coverage, the description adds meaning: message_id is 'as seen in mail_search/mail_read_thread output' and part_index is '1-based part index from mail_list_attachments'. This compensates fully.

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 the tool reads attachments and lists specific content types (text, PDF, image, office document, calendar invite). It distinguishes from siblings like mail_list_attachments which list attachments.

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 tells when to use this tool ('Call mail_list_attachments first to get a valid part_index'), mentions unsupported formats (archives and other binary formats), and implies alternatives for other operations.

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