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

Annotations already establish readOnly, non-destructive, closed-world behavior, and the description adds the substantive detail that the response aggregates usage records, matching orders, label surcharges, and return orders for one code. It omits volume/pagination limits and what happens when no shipment matches, which keeps it short of a 5.

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 sentences, zero filler: the action and its scope come first, then the payload contents. Nothing repeats the title or restates the obvious.

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 read-only lookup with no output schema, enumerating the returned record types is the right move and largely covers completeness. The gap is disambiguation: with InvestigateLabelByTrackTrace and LookupByTrackTraceBatch in the sibling set, the description should say why an agent picks this one, and it doesn't.

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 trackTrace and intentId are already documented in the schema. The description reinforces exact-match semantics of the tracking code but says nothing about the optional intentId correlation parameter, so it adds only marginal value over 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 ('Investigate') and resource ('a shipment') scoped to an exact track & trace code, then enumerates the returned record types. The 'exact' qualifier implicitly separates it from LookupByTrackTraceBatch, but the near-identical sibling InvestigateLabelByTrackTrace is never mentioned, so full sibling differentiation is missing.

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 'exact track & trace' framing implies this is the single-code lookup rather than the batch variant, which is useful implied guidance. However there is no explicit when-to-use / when-not statement and no pointer to InvestigateLabelByTrackTrace or GetLabelTrackingStatus, which an agent would need to choose correctly.

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