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

Annotations already declare readOnlyHint and openWorldHint, and the description adds substantive context beyond them: the mod-7 IATA check digit validation logic, the upstream data source (public track-trace.com carrier list), the $0.002 USDC x402 price with payment rails, and the policy that failed calls are not charged. Only finer operational details (error shapes, rate limits) are absent, and an output schema covers return values.

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?

It is a single dense paragraph with purpose front-loaded in the first clause and cost/limitation trailing, with no filler sentences. Slightly run-on, but every sentence carries information an agent needs.

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 single-parameter read lookup with an output schema and read-only annotations, the description covers everything material: input structure and validation, what the response contains (airline name, IATA code, cargo site, tracking link), the boundary of the tool (no live status), and the payment model.

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% and the schema already gives format and an example, so the baseline is 3. The description earns above baseline by decomposing the input (3-digit airline prefix + 8-digit serial) and stating the IATA mod-7 check-digit rule, which explains what validation the parameter undergoes rather than just its shape.

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?

The description names a specific verb set and resource: validates an 11-digit AWB, resolves the issuing airline and IATA code, and returns the cargo site plus tracking link. It is clearly separable from sibling tools like logistics_container_tracking, logistics_postal_upn_tracking, and logistics_vessel_tracker, and it even scopes out shipment status 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?

It gives the condition of use (you have an AWB and want carrier identification) and an explicit exclusion: it does not read shipment status because airlines publish that only on their own sites. That exclusion steers the agent away from expecting tracking data, though no sibling is named as an alternative for status lookups.

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