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

Annotations already declare it read-only and idempotent, but the description adds permission requirements (email:read and email:send), the exact return payload (draft, review_url, expiry, confirmation/send status), and an explicit non-action list. That is meaningful context beyond the structured hints.

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?

Four short sentences, each carrying distinct information: trigger, permissions, return contents, and exclusions/alternative path. Nothing is redundant and the trigger is front-loaded.

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?

With no output schema, the description compensates by enumerating return fields, and it also documents the auth scope and the non-actions. An agent has everything needed to call this correctly.

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% and the schema already explains that draft_id comes from prepare_email_draft and is not a message/event ID. The description adds no further syntax or format guidance, so the baseline 3 applies.

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 pairs a specific verb and resource ('Inspect a prepared draft') with a clear role boundary ('this connection's exact draft'), which an agent can distinguish from prepare_email_draft, send_email, and get_sending_status without opening the schema.

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?

It states explicit triggers ('after owner review or an uncertain send response'), explicit exclusions ('Does not approve, send or retry transmission'), and redirects the agent elsewhere when the status is unknown ('inspect the sent mailbox/provider'). When-to-use and when-not-to-use are both covered.

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