get_received_email_attachment

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

No annotations exist, so the description carries the full burden. It usefully discloses that the tool returns metadata (not raw bytes), includes download_url, and is a read-only retrieval of an existing attachment entry. This is sufficient for a simple metadata-fetch operation and clarifies what the agent will and will not receive.

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 sentences, no filler, and the core purpose is front-loaded. The parenthetical efficiently prevents confusion with the raw-bytes endpoint without expanding the description unnecessarily.

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 low-complexity metadata retrieval with two fully documented parameters, the description covers the essential behavior and return content. No output schema or annotations exist, but the description gives enough for an agent to select and invoke the tool correctly.

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 description coverage is 100%: both id and attachment_id are already described. The description adds no new parameter-level meaning beyond the schema, so the baseline score of 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?

Clearly states the operation: retrieve metadata for one attachment of a received email, including download_url. The description explicitly distinguishes this tool from the raw-bytes endpoint and implicitly from sibling get_email_attachment by restricting scope to received emails.

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 guidance by contrasting this tool with the raw-bytes endpoint and stating it returns the metadata entry instead. It could explicitly name sibling tools like get_email_attachment or list_received_email_attachments, but the distinction from the alternative HTTP endpoint gives practical usage context.

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