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

Annotations already establish read-only, non-destructive, closed-world behavior, so the description's added value is the batch cap and the stated return contents (labels, orders, surcharges keyed by track & trace). It does not cover partial failures or invalid-code handling, but it adds meaningful behavioral context beyond annotations.

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 no waste: the first covers scope and capacity, the second covers return contents. It is front-loaded and appropriately sized.

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 adequately discloses what is returned (labels, orders, surcharges keyed by track & trace) and the batch limit. Minor gaps remain around output shape and handling of invalid or partial track & trace codes, but the core call contract is covered.

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 parameters are documented in the schema. The description adds the important 200-code batch limit on trackTraces, which is not in the schema; intentId semantics remain delegated to the schema.

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 (lookup), resource (shipment/track & trace), and scope (batch up to 200), making it distinguishable from the singular LookupByTrackTrace. It does not explicitly name the sibling or contrast the two, but the batch scope is clear.

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?

The batch context and 200-code limit imply when to use it, but the description gives no explicit exclusions, prerequisites, or alternatives such as LookupByTrackTrace for single lookups or InvestigateLabelByTrackTrace for investigations.

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