get_mail_message_metadata

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

No annotations provided, so description carries full burden. Implies a read-only operation but does not confirm lack of side effects or specify what exactly is returned (e.g., which headers, mailbox data). Could be more transparent.

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 concise sentences: first states action and target, second states prerequisite. No fluff, front-loaded, efficient.

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?

For a simple tool with one parameter and no output schema, description is adequate. However, it could be more complete by listing types of metadata returned (e.g., subject, date, flags) or indicating the return is structured. Prerequisite is helpful.

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?

Single parameter message_id is fully described in the input schema (RFC 2822 with/without angle brackets). Tool description rephrases this but adds no new semantic value beyond what schema already provides.

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?

Description clearly states the action (read), resource (header and mailbox metadata), and method (by RFC message-id). It distinguishes from sibling tools like get_mail_detail (which may return full message) and get_mail_attachment.

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?

Mentions a prerequisite (Apple Mail indexing required) but does not explicitly state when to use this tool over alternatives like get_mail_by_rowid or get_mail_detail. No when-not-to-use guidance.

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