create-draft

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

With no annotations, the description fully discloses key behavior: 'creates a draft only and sends nothing', 'the user must open Mail.app and send it themselves', and notes low risk. It also specifies the return value (confirmation with recipients and attachment count), leaving no ambiguity about side effects.

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 concise and well-structured with labeled sections ('Use when', 'Returns', 'Do not use when', 'Safety'), front-loading the most critical information. Every sentence adds value without redundancy.

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 moderate schema coverage and absence of annotations, the description sufficiently covers usage, safety, and return value. It could optionally mention permission requirements or edge cases, but is complete enough for an agent to correctly invoke the tool.

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 coverage is 57%, so the description compensates by clarifying 'to/cc/bcc are arrays, optional attachments' and noting that attachments can be inline or paths. It also contextualizes parameters by stating 'safe default for any new message' and tying output to attachments count, adding meaning beyond the schema.

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 purpose: composing an email for user review in Mail.app before sending, distinguishing it as the safe default for new messages. It explicitly contrasts with send-email, making the resource and action unmistakable.

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 explicitly provides when to use ('when composing an email the user should review before sending') and when not to use ('when the user has already confirmed they want it sent now'), naming the alternative (send-email). This is exemplary guidance.

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