Drafts

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

The annotations only indicate readOnly=false and destructiveHint=true, so the description carries real weight here. It adds non-obvious behavioral detail: IMAP draft_ids change on every update, signatures are embedded at create/update time, send transmits the stored body as-is to avoid double signatures, and reply/send require specific scopes. No contradiction with annotations exists.

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 four sentences, front-loaded with the core purpose, followed by the most important operational caveats. Every sentence adds distinct information with no filler or repetition.

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 15 parameters and 6 actions, the schema carries most structural detail and the description supplies the missing operational context: draft_id freshness, signature behavior, and permission requirements. It is not a 5 because it does not enumerate the possible actions or mention return-value expectations, though the lack of an output schema lowers that burden.

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 baseline is 3. The description adds value beyond the schema by clarifying that include_signature is embedding on create/update and that send uses the stored body verbatim, which prevents a common double-signature mistake. It does not need to repeat every parameter because the schema already documents them thoroughly.

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 that the tool manages unsent drafts and the action enum spells out six concrete operations (list, create, reply, update, send, delete), so an agent can identify its purpose. It stops short of 5 because 'Manage' is a generic verb and no explicit contrast with sibling tools such as email_compose is provided.

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 resource 'unsent drafts' implies the main use case, and the schema action descriptions give within-tool guidance for choosing list versus create versus reply, etc. However, the description never names alternative sibling tools or states when not to use this tool, so the guidance is implied rather than explicit.

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