mail_list_inbox

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

Annotations already cover read-only and non-destructive behavior, and the description does not contradict them. It adds the useful context that the inbox is 'synthetic' and tied to a 'configured identity', but it does not disclose limit/pagination behavior or what fields the metadata contains.

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 short sentence with no fluff, and the key verb and resource are front-loaded. Every word contributes meaning.

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 read-only tool with one optional parameter and strong annotations, the description is mostly sufficient. However, with no output schema, it should clarify what 'inbox metadata' actually contains and how the limit parameter shapes the result.

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 single parameter `limit` has clear constraints in the schema, but schema_description_coverage is 0% and the description never mentions the parameter. Since the coverage is low, the description should have compensated by explaining how the limit affects the returned inbox metadata; it does not.

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 names a specific verb ('Read'), a resource ('synthetic inbox metadata'), and a scope ('for the configured identity'). It is clearly distinct from the sibling mail_prepare_draft, which is a compose/write action. It falls short of 5 because 'metadata' is somewhat ambiguous about whether it returns message summaries, counts, or other fields.

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?

There is no guidance about when to use this tool versus alternatives, nor any mention of prerequisites such as identity configuration. The intended use must be inferred from the name and the generic read description.

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