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

With only coarse annotations (readOnlyHint/destructiveHint/idempotentHint), the description carries the important disclosure: the call itself changes nothing, it returns a preview plus a confirmation link, and only the merchant can execute the change. That auth/execution model is exactly the context annotations cannot express. It stops short of covering edge behavior such as multi-parcel ambiguity or the notify email side effect.

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?

The purpose and the 'changes nothing / merchant confirms' caveat are front-loaded and compact. One sentence is wasted, however: 'Money is integer minor units (cents)' has no bearing on any parameter of this tool and risks confusing an agent about a money field that does not exist.

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 6-parameter tool with no output schema and thin annotations, the description supplies the essential missing piece — that the return value is a preview and confirmation link, not an applied change. Remaining gaps are minor: behavior when an order has multiple parcels and `find` is omitted, and the effect of `notify`.

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 the schema already documents every parameter (find, carrier, carrierName, trackingNumber, notify, orderNumber). The description adds nothing parameter-specific — its only numeric sentence concerns 'integer minor units (cents)', which is irrelevant here since no money parameter exists. 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?

The first sentence gives a specific verb and resource: 'Correct a parcel's carrier or tracking number.' That is enough to distinguish it implicitly from siblings like orders_remove_shipment or orders_mark_delivered, but no sibling is named and no scope boundary (e.g. 'this edits an existing parcel only') is drawn 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?

Usage is implied: call it when a parcel's carrier or tracking details are wrong. The description also signals a relevant precondition (the merchant must confirm on the returned page, so this is a request-for-change rather than a direct edit), but it never names alternatives or says 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.