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

No annotations are provided, so the description must convey behavioral traits. It correctly implies a read operation (list messages) but does not disclose whether the token is consumed, if the operation is idempotent, or any side effects. The mention of the token being from mail_inbox_create adds some context.

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 a single, front-loaded sentence with no wasted words. It conveys the core purpose and a critical prerequisite efficiently.

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 list tool with three parameters and no output schema, the description is minimal. It does not describe the return format, how optional parameters affect results, or any other behavioral context beyond the token requirement. This leaves significant gaps for an agent to use the tool 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?

With 0% schema description coverage, the description must explain all parameters. It only explains the 'token' parameter (requires from mail_inbox_create), leaving 'address' and 'inbox_id' unexplained. This is insufficient for a 3-parameter tool where the schema provides no descriptions.

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 it lists messages in a temp inbox, using a specific verb and resource. It also mentions the token requirement, which helps distinguish it from related tools like mail_inbox_create and mail_inbox_read, though it could be more explicit about the difference.

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 only provides a prerequisite (token from mail_inbox_create) but offers no guidance on when to use this tool versus alternatives like mail_inbox_read, or when not to use it. No exclusion criteria or context-dependent usage advice is given.

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