Get shipment

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the bar is lower, and the description still adds real value: costs are in US dollars, adjustments include the carrier-corrected weight/size with price delta and dispute state, and it discloses print/refund eligibility flags. It does not cover pagination or partial-failure behavior, but for a read-only fetch that is minor.

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 one-line summary is front-loaded ahead of the field inventory, which is appropriate given there is no output schema. The second sentence is long but each listed field earns its place as the only documentation of the return payload; 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?

With no output schema, the description carries the return-value burden and does so thoroughly: status, carrier/service/zone, tracking, recipient, package, cost breakdown with surcharges and insurance, estimated delivery, originating order, print/refund capability, and carrier adjustments. An agent knows what it will get without opening anything else.

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 both shipment_id and the optional batch_id are already documented in the schema (including batch_id's 'saves one request when known' purpose). The description adds no parameter syntax or constraints beyond that, so the baseline 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?

Opens with a specific verb-and-resource statement (one shipment with tracking, service, cost, recipient, carrier adjustments) and the second sentence enumerates exactly what the single record contains. It implicitly contrasts with list_shipments by saying 'One shipment', though it never names the sibling explicitly.

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?

Usage is only implied: fetch a single shipment by id. There is no statement of when to prefer this over list_shipments or get_batch, and no prerequisites; the only routing hint lives in the shipment_id schema text ('From get_batch or list_shipments'), not the description.

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