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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely new behavioral context: results are scoped to the authenticated account and returned newest first, which affects how an agent consumes the list. Return shape and paging limits are left to the schema.

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, zero filler, with the core operation and ordering front-loaded and the sibling reference last. Every clause adds 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?

For a three-param list tool with no output schema and full annotation coverage, this is nearly complete: purpose, scope, ordering, filtering and the sibling alternative are all present. It does not describe the shape of returned shipment entries, which an agent must infer.

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 baseline would be 3, but the description adds value by naming example status values ('Delivered', 'In Transit') where the schema declares no enums, and by confirming limit/offset are a paging pair. That meaningfully reduces guesswork on the unconstrained status string.

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 plus scope ('on the authenticated account') and default ordering ('newest first'). It explicitly distinguishes itself from get_shipment, so an agent can separate the list operation from the single-record sibling without opening a schema.

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?

Gives clear routing guidance with 'Use get_shipment for the full record of one shipment' and notes paging/filtering support. It stops short of covering the other nearby siblings (track_package, list_addresses), so the when-not coverage is good but not exhaustive.

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