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

Annotations already mark this as read-only, idempotent, and non-destructive, but the description adds meaningful behavioral detail: the exact response shape, pagination via next_page_token, and the fact that list items carry only preview while full text/html requires get_agentmail_draft. No contradiction with annotations.

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 somewhat long and repeats the 'every inbox in the account' idea twice, but it is well-structured, front-loads the core purpose, and each sentence adds distinct information such as response fields, preview-only behavior, and sibling routing.

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 rich output schema, annotations, and sibling context, the description covers everything needed to select and call the tool correctly. It explains scope, pagination, list-vs-detail behavior, and the discriminant between this and the inbox-scoped sibling.

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 schema documents all seven parameters. The description adds value by explaining pagination and response fields, but it provides no additional detail about the parameters themselves. This matches the baseline for fully covered schemas.

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 states a precise action and resource: listing unsent drafts across every inbox in the account. It clearly distinguishes itself from the inbox-scoped sibling get_agentmail_inbox_drafts, so an agent can identify this tool without opening schemas.

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 explicitly explains that this is the organization-wide view spanning every inbox, and that the inbox-scoped twin get_agentmail_inbox_drafts should be used when a single inbox is intended. It also notes that all AIsa callers share one account, giving a concrete reason to prefer the scoped alternative.

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