download_attachment

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

No annotations are provided, so the description must bear the burden. It discloses that the tool downloads to disk and returns file path and size, but does not mention overwriting behavior, directory creation, authentication needs, or rate limits. Some behavioral context is provided via default save directory, but gaps remain.

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, with a clear first sentence stating the tool's purpose, followed by an Args list and a Returns line. Every sentence adds value, no redundancy or fluff.

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 tool with 4 parameters and no output schema, the description covers the core functionality, inputs, and output. It could mention error handling or required prior authentication, but given the context of sibling email tools, it is reasonably complete.

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 description coverage, the description explicitly explains each parameter's meaning and source (e.g., 'Email ID from search_emails() result', 'Attachment filename to download (from read_email attachments list)'). It also documents the default for save_dir. This fully compensates for the lack of schema descriptions.

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 action (Download) and the resource (an email attachment to disk). It is specific and distinct from sibling tools like fetch_part, which might involve fetching but not saving to disk.

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 prerequisites by referencing 'search_emails()' and 'read_email', but does not explicitly state when to use this tool over alternatives or when not to use it. No exclusions or alternative tool recommendations are provided.

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