download_attachments

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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint, covering safety and idempotency. The description adds the base64 format detail but omits other behavioral traits like potential large payloads or that missing filenames returns all attachments. No contradictions.

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 with no wasted words. The first sentence fronts the core purpose; the second provides actionable guidance. Highly efficient.

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?

Given the tool's simplicity, annotations covering safety, and presence of an output schema, the description is largely sufficient. Minor omission: does not mention that omitting filenames downloads all attachments, but this is inferable.

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 50% (uid and filenames described). The description adds meaning to filenames (saving byte cost) but does not elaborate on folder or account parameters. Overall, it adds some value beyond the schema but leaves gaps.

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?

Description clearly states the tool returns message attachments in base64 format, with an option to filter by filenames. It specifies the exact resource and action, distinguishing it from sibling tools which focus on reading email content or managing folders/stars.

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 a usage hint ('Filter by filenames to save bytes'), which helps agents know when to leverage filtering. However, it does not explicitly state when to use this tool versus alternatives (e.g., read_email), though as the only attachment downloader, context is clear.

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