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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the description's statement that it 'removes it from Drafts' aligns with and reinforces the annotation. The description adds value beyond annotations by disclosing that attachments are included and that recipients must match send_allowlist. It does not contradict 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?

Two sentences with no filler. The core action and the most important side effect (removal from Drafts) are front-loaded, and the recipient constraint is stated clearly. Every sentence earns its place.

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 destructive send operation, the description covers the key facts: what is sent, what happens to the draft, and the recipient constraint. It does not describe the return value or error cases, but there is no output schema and the annotations cover the safety profile. The description is complete enough for an agent to invoke the tool 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%, so the schema already documents all three parameters. The description adds context that the uid comes from create_draft or search_messages in the Drafts folder, which is already in the schema. The description does not add much beyond the schema, but the baseline of 3 is appropriate because the schema carries the full burden.

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 specific verb ('Sends'), a specific resource ('a draft exactly as stored in the Drafts folder'), and key behavioral details (includes attachments, removes it from Drafts). It clearly distinguishes this from siblings like send_message (which sends a new message) and reply_send (which sends a reply).

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 implies when to use this tool: when you have a saved draft and want to send it exactly as stored. It also notes that recipients are taken from the draft and must match send_allowlist, which is a critical usage constraint. It does not explicitly name alternatives or say 'use send_message instead when...', but the context is clear enough for an agent to select it.

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