get_email_metadata

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

No annotations are provided, so the description carries the full burden. It discloses what is returned (headers/metadata) and what is not (body, preview), and mentions the return shape as a restricted JMAP Email object. However, it does not discuss performance, rate limits, or authentication requirements, which would enhance transparency.

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 yet comprehensive, stating the main purpose first, then listing specific fields, followed by use-case examples. Every sentence adds value, and there is no redundancy. It is well-organized and easy to parse.

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 only one parameter and no output schema, the description adequately explains what the tool returns. It covers the header-only restriction and how it differs from full email retrieval. However, a brief note about the return structure (e.g., JMAP Email object) could be more explicit for completeness.

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?

The input schema has 100% description coverage for the single parameter 'emailId', so baseline is 3. The description does not add further details about the parameter's format or constraints beyond the schema, but the overall tool context implies its purpose. No additional semantic value is provided.

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 function: retrieving email headers/metadata. It explicitly lists the fields included (sender, recipients, subject, etc.) and those excluded (body, preview, rendered text), distinguishing it from siblings like 'get_email'.

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 provides explicit usage scenarios, such as classifying or routing emails without ingesting content, and gives concrete examples like least-privilege flows and verifying post-archive placement. This helps the agent decide when to use this tool instead of alternatives.

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