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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuine business context beyond that: the buyability verdict depends on published prices and payment limits, which an agent could not infer from the annotations or schema. It does not cover failure modes for unknown SKUs or out-of-stock lines.

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?

One compact sentence with the key outputs front-loaded and no filler. It is a sentence fragment rather than a full clause, which slightly hurts readability but wastes nothing.

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?

An output schema exists, so return values need not be described, and the description supplies the decision rule that makes the response interpretable. Missing only edge-case behavior (invalid SKU, zero stock) and an explicit pointer to request_quote for the quote path.

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% and there is a single parameter, so the schema already explains items, SKUs, quantities and the selling-unit convention. The description only restates 'a list of items' without adding format, limits, or batching guidance, so 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 description names the concrete outputs — per-item price and stock, the subtotal, and a buy-online-now vs. needs-a-quote determination — which is far more specific than the title. It implicitly separates itself from get_product (single item) and request_quote (quote path), but never names those siblings, so the differentiation is left to inference.

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 only implied: the phrase 'needs a quote' hints that request_quote is the follow-up path, and the pricing/payment-limit logic suggests this is a pre-checkout check. There is no explicit statement of when to call this versus get_product or get_shipping_estimate, and no stated prerequisites.

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