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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), but the description adds real value: sign-in is required, the offer is re-checked for freshness, and it explicitly is not an order placement despite the 'buy' in the name. It stops short of explaining link staleness/expiry behavior, which keeps it from a 5.

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?

Four short sentences, each carrying distinct information (what it returns, auth requirement, when to call, what it is not), with the core action front-loaded and no redundancy.

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 an output schema present, return-value detail is unnecessary, and the description still covers auth, input sourcing, valid-offer preconditions, and the no-order-placement clarification. Nothing an agent needs to invoke it correctly is missing.

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 0%, so the description must compensate, and it does by naming all four required inputs and their origin (the exact styleId, styleProductId, offerId and delivery country from style-purchase-options-by-id). It does not explain the format expectations (hash patterns for offerId/styleProductId) or the country enum, so a small gap remains.

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 states a specific verb+resource (recheck a purchase offer, return its current retailer link) and clarifies the scope against the name's misleading 'buy'. It implicitly distinguishes itself from the feeder sibling style-purchase-options-by-id, so an agent can tell what this tool does without opening the 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?

It names the exact precondition (only when the user wants to open a retailer), the required sibling that supplies the inputs (style-purchase-options-by-id), and an explicit exclusion (do not call for offers with canBuy false). This is when-to-use, when-not, and the alternative all in one.

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