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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false, so the safety profile is covered structurally. The description adds real context beyond that: deletion is permanent, human confirmation is required, and a previously sent email derived from the draft survives. That scope-of-destruction detail is genuinely useful.

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 short sentences, front-loaded with the core action, with zero padding. Every clause carries information.

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?

An output schema exists, so return values need not be explained. Combined with annotations covering the safety profile, the description supplies the two non-obvious behavioral facts an agent needs (permanence and the surviving sent email). Only the identification of the draft_id source is unaddressed.

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?

There is 1 parameter at 0% schema description coverage, and the description provides no information about draft_id (format, where to obtain it, or validity). The name and UUID format are self-evident from the schema, but the description does nothing to compensate for the coverage gap.

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 (delete) and resource (draft) with the modifier 'permanently', so the agent can tell it apart from delete_message, delete_thread, and delete_sent_message by resource. It does not explicitly name a sibling to contrast with, but the resource naming makes the target unambiguous.

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?

There is one clear prerequisite: confirm with the human before deleting. However, it gives no guidance on when to prefer this over related delete tools or what to do if the draft does not exist. Usage is implied rather than spelled out.

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