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

This is a strong disclosure: it explains that the call refreshes stale carrier data and persists tracking events, which is exactly why readOnlyHint=false, and it clarifies that read-only credentials get stored status without refresh or persist. It also documents the notFound behavior for out-of-scope ids — meaningful side effects the annotations alone could not convey.

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 short sentences, front-loaded with the core purpose, followed by side effects and the credential caveat. Every sentence carries distinct information and nothing is repeated.

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 covers the key return nuance (notFound for out-of-scope ids) and the mutation side effects. The main remaining gap is the lack of routing guidance against the near-duplicate single-id and tracking-status siblings.

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 description coverage is 100%, so both parameters are already documented; the description only restates the 'max 100' limit on labelIds. It adds nothing about intentId, the correlation ID parameter, beyond what the schema says. 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 with scope: 'Shipment status for up to 100 label ids.' An agent immediately knows this is a batch status lookup. It does not, however, distinguish itself from the very similar siblings GetShipmentStatus (singular) or GetLabelTrackingStatus, leaving ambiguity about which to pick.

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?

Batch usage is implied by the 'up to 100 label ids' framing, and the read-only-credential branch is described, but the description never says when to choose this over GetShipmentStatus or GetLabelTrackingStatus. There are no explicit exclusions or alternatives named despite several overlapping siblings.

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