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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered elsewhere. The description adds only that relationships can be embedded and echoes the endpoint path; it says nothing about 404 behavior, whether missing relationships are silently omitted, or any rate limit.

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 compact fragments with zero filler; the scope statement leads and the endpoint reference trails. Nothing can be cut without losing information.

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 carries some burden for describing the returned shipment object's shape, and it offers none — an agent learns which relationships can be attached but not what the payload contains or how embedded relationships are keyed. Adequate but with a real gap.

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 the baseline is 3, but the description genuinely adds value: it enumerates the valid relationship names (customer, fulfillments, labels, ship_address, subscriptions), which is more useful than the schema's generic example 'customer,orders' that does not obviously apply to shipments.

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 and resource — retrieving one shipment by id — and even pins the REST endpoint, so an agent can immediately tell it apart from cratejoy_list_shipments. It stops short of explicitly contrasting itself with the list sibling, which is all that separates it from a 5.

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 by the 'by id' framing and the required shipment_id, so the agent knows this is a single-record fetch rather than a listing. However, there is no explicit when-to-use guidance, no mention of what to do when the id is unknown or when relationships should be omitted, and no named alternative.

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