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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world scope, so the safety profile is covered. The description usefully adds that the output is non-binding and enumerates the cost components, but says nothing about precision, assumptions, or whether results are cached/live.

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?

Two tight sentences with the core purpose front-loaded and the caveat second; each sentence earns its place. Slightly more compressed phrasing of the cost list could tighten it further, but there is 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?

For a six-parameter, fully documented, read-only estimator with no output schema, the description suffices: it explains what the estimate spans and warns that it is not binding. Only a hint about how air versus sea inputs are consumed would add materially.

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 100% with enums on lane and category, so the schema already carries parameter meaning. The description's component list (freight, insurance, duty, VAT, levies, fee) loosely maps to the inputs but adds no syntax or format detail beyond the schema, warranting the baseline 3.

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?

Names a specific verb-and-resource pair ("planning estimate of the full delivered price in Uganda") and itemizes the cost components included, so the agent knows exactly what it computes. It stops short of naming a sibling alternative or explicitly contrasting scope with, say, get_payment_options, so it is clear but not fully differentiated.

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?

Establishes a clear usage boundary: it is a planning estimate, not a final quote, and final quotes require written supplier and shipping prices. It does not state explicit preconditions (e.g., classify the product first) or name alternatives, so the guidance is contextual rather than routing.

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