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

The description discloses behavior the annotations cannot: it refreshes carrier status only when older than 12 hours, persists tracking events and changed status fields, and degrades to stored-only reads for read-only credentials. This coherently explains why readOnlyHint is false and openWorldHint true, giving the agent a real picture of side effects and freshness.

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?

Three dense sentences with zero padding: purpose first, side effects and refresh policy second, credential caveat third. 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?

With no output schema, the description still conveys the return concept (current status, tracking events) and the API mapping. It stops short of describing the response shape or what 'status fields' means, which would be the last gap for a tool with no output schema.

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 labelId and the optional intentId correlation ID are already documented. The description adds no parameter-level detail beyond 'one label', 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?

States a specific verb and resource: 'Current shipment status for one label.' The 'one label' scoping implicitly distinguishes it from the plural sibling GetShipmentStatuses, but it never names GetLabelTrackingStatus or GetLabelsForOrder, so the agent must infer differentiation.

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 defines a real usage condition — read-only credentials get stored status without refreshing — which is genuinely useful. However, it gives no explicit when-to-use guidance versus the closely related siblings (GetShipmentStatuses, GetLabelTrackingStatus), leaving routing to inference.

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