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

Annotations carry the safety profile (destructiveHint=false, idempotentHint=true, openWorldHint=true), so the description does not need to restate them. It adds useful content scope (ETA confidence, AI narrative) but nothing extra about behavior such as auth needs, rate limits, or freshness/caching of carrier data. Note the readOnlyHint=false annotation sits oddly with a pure retrieval tool, but the description itself makes no contradicting behavioral claim.

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, content scope front-loaded, and the usage cue placed last. No filler or repetition of the schema.

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?

An output schema exists, so return values need not be detailed, yet the description helpfully previews the payload fields. With full schema coverage on the single required parameter and annotations covering safety, the only minor gap is error/permission behavior.

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?

Only one parameter, and the schema already covers it at 100% with concrete format examples (MRKU5004867, SEGU3103001). The description adds no further semantics beyond identifying which container to query, 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?

Specific verb (fetch) plus resource (a single container) with an explicit enumeration of the returned content: status, route, ETA with confidence, carrier, vessel, events, and AI narrative. It is clearly distinguishable from a multi-container/summary sibling, though no sibling is named 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?

"Use this when asked about a specific container" gives a clear selection trigger scoped to one container, which implicitly separates it from shipment-level siblings. It stops short of naming the alternative (e.g., get_shipment_summary) or stating when not to use it.

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