compare_shipping_plans

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

Annotations already declare readOnly, idempotent, non-destructive and open-world behavior, so the safety profile is covered. The description adds useful context beyond that: results are estimates from supplied data, not live rates, and exclude taxes/duties/payments — meaningful scoping of what the calculation does.

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; the capability and its criteria come first, followed by input requirements and exclusions. Every clause 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?

For a complex nested-input tool with no output schema and low schema description coverage, the description explains purpose and boundaries well but is thin on how the nested structures (offers, fulfillment_groups, constraints) relate and what the comparison returns. Adequate for routing, incomplete for confident invocation.

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 only 20% and the schema is deeply nested, so the description must compensate. It gestures at the right inputs (prices, quantities, merchant/warehouse rules, single currency, no conversion) but never mentions destination, constraints (max_shipments, max_delivery_days), offer/group linkage, or minor-unit encoding.

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?

States a specific verb (Compare) plus resources (complete-basket offers and shipping methods) and the three optimization criteria (lowest cost, fastest delivery, fewest shipments). It does not explicitly name siblings like compare_offers, but 'complete-basket' implicitly distinguishes it from single-item offer comparison.

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 clear usage context ('supply prices, quantities and merchant/warehouse rules in one currency') and a strong when-not list of exclusions (no live rates, stock checks, taxes, duties, purchases or payments). No named alternative tool is offered, so it falls short of a 5.

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