hey_download_attachment

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

Details the save location, auto-numbering of duplicates, and return values. The annotations (not readOnly, not destructive, not idempotent, openWorld) are consistent; the description adds context about file creation behavior without contradiction.

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: first states the core function, second provides the workflow and return format. Every part earns its place, no filler, ideally front-loaded.

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?

Covers the workflow and return structure clearly, but does not mention error handling (e.g., invalid attachment_id, missing email). For a simple download tool, this is acceptable but could be more 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?

Schema coverage is 100%, and the description enriches each parameter: email_id explains automatic topic ID resolution, attachment_id references the source array, and save_path details defaults, directory interpretation, and duplicate handling. This goes well beyond the schema alone.

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 verb 'download', the resource 'attachment from an email', and the outcome 'save it to disk'. It distinguishes itself from all sibling tools, as none other deal with downloading 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?

Provides explicit guidance to first call hey_read_email to retrieve attachments, then use this tool with the attachment_id. This primes the agent on the correct workflow, and no alternatives exist among siblings.

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