gmail_get_attachment

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

With no annotations provided, the description carries the full burden and does well: it discloses the return format ('Returns file path and metadata (no binary data in response)'), the side effect of saving to disk, and the permission requirement ('Requires readonly scope'). It could add error-handling details, but the essential behaviors are covered.

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 three sentences long, front-loaded with the primary action, and every sentence adds value. There is no fluff or redundancy.

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 required parameters, no annotations, and no output schema, the description provides the key context: the prerequisite workflow, return format, and read-only scope. It is sufficiently complete for an agent to understand the tool's behavior and usage.

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%, so the baseline is 3. The description does not add substantial parameter-level detail beyond the schema; the mention of using gmail_list_attachments is already captured in the filename parameter schema description.

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 specific action: 'Download an attachment from a Gmail message and save it to local disk.' It uses a specific verb and resource, and distinguishes from siblings like gmail_list_attachments by referencing the prerequisite and return format.

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?

It provides clear context by instructing 'Use gmail_list_attachments first to get filenames,' establishing a prerequisite workflow. However, it does not mention alternatives like gmail_bulk_save_attachments or explicitly state when not to use this tool.

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