gmail_get_attachment

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

Annotations already establish readOnlyHint and openWorldHint, so safety is covered. The description adds genuinely useful behavioral context beyond that: the return format (base64) and, importantly, a ~2 MB size ceiling that signals the call may fail for large attachments.

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?

A single short sentence, front-loaded with the action and ending with the constraint. No filler whatsoever.

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 simple annotated read tool the description covers what it returns and the size limit, which is largely adequate. However the undocumented 'filename' matching semantics and the absence of any routing relative to gmail_get_message leave an agent with unanswered questions before a call.

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 only 50% — 'id' is documented (cross-referencing gmail_search/gmail_list_drafts) but 'filename' has no description anywhere. The description adds nothing about how the filename must match (exactness, case, multiple matches), so the gap is left unclosed.

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?

States a specific verb (download) and resource (attachment), plus the output format (base64) and a size cap. It is clearly distinguishable from gmail_get_message since no sibling performs attachment downloads, but it never explicitly contrasts itself with the message-retrieval tools.

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?

No when-to-use guidance, no prerequisites, and no mention of alternatives such as gmail_get_message. The agent is left to infer that this is the tool for retrieving attachment bytes from a known message.

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