Read Gmail Attachment (read-only)

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

Discloses non-obvious behavior beyond annotations: text formats return utf-8, binary types return metadata only with no base64 dump, share tokens are blocked, and there's a cost ($0.10). These are exactly the operational details annotations don't cover.

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?

Dense, front-loaded single paragraph covering purpose, sourcing, output behavior, auth, and cost. Every clause earns its place with no 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?

Output schema exists, so return format needn't be explained, yet the description still clarifies format-dependent behavior. Auth constraints, cost, and ID sourcing are all present, making it fully complete for a 4-param read tool.

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 0%, so the description must compensate. It explains message_id and attachment_id sourcing (from read_gmail_message.attachments), which is critical since the schema provides no descriptions. Optional account/email aren't clarified, but the core required parameters are well-documented.

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?

Specific verb (download) plus resource (Gmail attachment) with exact identifying parameters. The reference to read_gmail_message.attachments explains where the IDs come from, distinguishing it from search_gmail and read_gmail_message.

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?

Explicit prerequisites: needs message_id + attachment_id from read_gmail_message.attachments. Names the auth conditions: share tokens cannot call, API key required. An agent can determine eligibility without trial-and-error.

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