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

With no annotations, the description carries the full burden and does disclose the central behavior: carriers bill on the greater of actual vs cubic weight, and the tool returns the cubic weight under each convention plus the charged weight. It lacks explicit statement of side effects (none) or precision/rounding behavior, but for a stateless calculation this is close to complete.

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?

Three tight sentences: rationale, then inputs and returns, then the pre-quoting usage rule. The opening motivation sentence is slightly ahead of the core action, but every sentence earns its place with no filler.

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?

There is no output schema, and the description compensates by describing the return values (cubic weight under each common convention and the weight actually charged). For a four-parameter, side-effect-free computation, nothing an agent needs to call it correctly is missing.

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 coverage is 100%, so the four inputs (length/width/height in cm, weight in kg) are already fully documented in the schema. The description adds only the framing that dimensions and actual weight together determine the result, not new per-parameter meaning, so the schema-does-the-work baseline of 3 applies.

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 computation (cubic/volumetric weight and chargeable weight from dimensions and scale weight) and explains the domain rule behind it, so an agent can distinguish it instantly from the quote_* and lookup siblings. The title reinforces rather than merely restates the name.

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?

It explicitly says to use it before quoting so the weight passed to a quote tool matches what will be billed, which is clear routing guidance relative to quote_domestic_au and quote_international_from_au. It does not state any when-not-to-use case, but for a pure calculation tool the context is unambiguous.

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