mail_send_draft

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

Annotations are sparse (no readOnlyHint, destructiveHint false). The description adds value by specifying the return value (`id`). It does not contradict annotations, but could mention if sending a draft is irreversible or if any side effects occur. Still, it provides useful behavioral context beyond 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?

The description is only three sentences, each sentence serves a distinct purpose: purpose, usage, return value. It is front-loaded and contains no fluff.

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's simplicity (4 params, no nested objects), the description covers the core behavior, usage in context of other mail tools, and return format. It does not discuss error cases or prerequisites like draft existence, but it is adequate for the minimal complexity.

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 0%, so the description must compensate. It explains `to` and `in_reply_to` but does not describe `subject` or `body`. However, `subject` and `body` are self-explanatory. Partial coverage, but not fully compensating for all parameters.

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 verb ('Send'), resource ('draft email'), and origin ('from Hermes's account'). It differentiates from sibling tools like mail_get by specifically indicating sending drafts, and provides context for replying.

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 tool description tells when to use it (to send drafts) and provides specific guidance: use the `sender` from mail_get as destination, and pass `in_reply_to` for thread replies. It does not explicitly state when not to use it, but the context is clear enough.

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