create_draft

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

No annotations are provided, so the description must carry the full burden. It discloses that the tool does not send and that scheduling/reply are optional, which is useful. But it omits other important behaviors like permissions, idempotency, what happens with a future scheduled_at, or what the response contains.

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 a single, front-loaded sentence that contains only necessary information. It is concise and structured in a clear order: create, optional behavior, and explicit limitation.

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 tool has 7 parameters, no output schema, and no annotations, the description is too sparse. It doesn't explain return values (e.g., draft ID), clarify whether both html and text are needed, or detail how scheduled drafts behave, leaving significant gaps for an agent.

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 only 29% (2 of 7 parameters). The description adds meaning for scheduled_at ('optionally scheduled') and reply_to_message_id ('optionally a reply'), but provides no context for html, text, subject, to, or inbox_id, forcing agents to rely solely on parameter names.

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 clearly states the tool's verb ('Create') and resource ('a draft'), and explicitly mentions optional scheduling and reply behavior. It also says 'Does not send,' which differentiates it from sibling tools like send_message and send_draft.

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 usage: when you want to create a draft rather than send a message immediately, with optional scheduling or reply. However, it does not explicitly name alternative tools for sending, such as send_message or send_draft, so the guidance is implicit rather than fully explicit.

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