Get Attachment Metadata

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

Annotations confirm idempotent and read-only behavior. The description adds context about the short-lived download URL and the need to call the tool again if it expires, which is valuable beyond annotations.

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 concise, consisting of two sentences that front-load usage guidance and key behaviors without waste.

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?

With an output schema present, the description covers behavioral context sufficiently. It explains the URL expiration and usage flow, making it complete for an agent.

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%, so parameters are well-documented. The description does not add extra parameter details, but it is not necessary given the schema's completeness.

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 returns metadata and a download URL for a message attachment, which is specific and informative. It does not explicitly differentiate from sibling tools like mailbox_read_attachment, but the purpose is 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 advises to use this tool after finding an attachment and to fetch the URL promptly due to expiration, providing actionable usage guidance. It lacks explicit when-not-to-use or alternative tools, but the instructions are clear.

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