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

Annotations already declare readOnlyHint/idempotentHint/destructiveHint, and the description adds only a 'supported' qualifier indicating results are restricted to supported routes. It does not describe return payload or empty/error behavior, but the annotation safety profile covers the main behavioral burden.

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?

A single sentence with no filler, front-loading the verb and resource. The mismatch between title 'Calculate' and description 'Retrieve' is a minor wording issue.

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 tool with no output schema and an anyOf input contract, the description is too thin: it omits how the port/port_id parameters participate and what response shape to expect. An agent could guess the input contract only partially.

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?

Schema description coverage is 0%, so the description must compensate. It explains vin and lot_number as accepted lookup keys but never explains port/port_id or the anyOf one-of requirement. This partial coverage earns a 2.

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 action ('Retrieve'), a concrete resource ('auction-to-port shipping information'), and the accepted identifiers ('VIN or lot number'), distinguishing it from the vehicle-listing siblings. The title reinforces the resource. It lacks an explicit exclusion of sibling tools, so not a 5.

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?

Gives a conditional context: use when location and route data are available, with identifier choice. It does not name alternatives or when-not conditions, but none of the sibling tools cover shipping, so the context is fairly clear.

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