download_attachment

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

With no annotations, the description carries full burden. It clearly states the behavioral difference: file write vs base64 return. However, it does not disclose potential side effects (e.g., file overwrite, size limits) or error conditions.

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 concise sentences with front-loaded key information. Every sentence adds value, no 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?

The description covers the two return behaviors adequately given the output schema exists. However, it lacks context on prerequisites (e.g., attachment_id from list_attachments) and error handling, which would make it more complete for a tool with 5 parameters.

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 0%. The description only explains the effect of save_to; it does not provide additional meaning for other parameters (message_id, attachment_id, account, folder) beyond their names.

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' and the resource 'an attachment', and explains the dual behavior (save_to vs base64). It distinguishes itself from siblings like list_attachments (which lists metadata).

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 explains two usage modes (with save_to or without) but does not specify prerequisites (e.g., need attachment_id from list_attachments) or when to use this tool over alternatives among the many sibling email tools.

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