Refresh mail

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

The description adds the behavioral detail that it reports a before/after snapshot, which goes beyond the annotations. It also notes that it asks Mail.app, indicating an external app interaction. Since annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, the safety profile is covered. The description provides a bit of extra context but does not disclose any limitations or side effects beyond what the parameters suggest (wait and timeout).

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 one sentence with no filler; it gets straight to the point. It front-loads the main action ('fetch new mail') and then adds the snapshot detail. It is concise and structured well, though it could arguably include a bit more structured detail, but it earns its place with its efficiency.

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 (two optional parameters, high schema coverage, and annotations covering safety), the description is mostly complete. It mentions the before/after snapshot, which is a key output behavior. The output schema exists, so return values need not be explained. The only minor gap is that it doesn't mention any prerequisites like Mail.app being running, but that is likely implied. Overall, an agent has enough to call it correctly.

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 schema description coverage is 100%, with both parameters (wait_seconds and timeout_seconds) fully described in the schema. The tool description does not add any parameter-specific information, but per the rubric, a baseline of 3 is appropriate when the schema covers the parameters comprehensively. No additional semantic value is provided by the description.

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 that the tool asks Mail.app to fetch new mail and reports a before/after snapshot. This is a specific action on a specific resource, and the snapshot detail adds unique behavior. However, it does not explicitly distinguish itself from sibling tools like search_emails or list_recent, though the verb 'refresh' and the snapshot concept make its role clear enough.

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 that this tool is for fetching new mail, which is a clear context for when to use it. However, it provides no explicit guidance about when not to use it or mentions any alternatives such as search_emails or get_email. The usage is implied by the action itself, but there is no direct comparison or exclusion.

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