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

Annotations already declare a read-only, non-destructive, closed-world read, so the bar is lower; the description still adds real behavioral context — batching semantics (up to 8, answered in order), the concurrency rationale against parallel calls, and the exact price definition (median of one-per-retailer, new, in-stock offers' unit prices). It does not disclose result size, truncation, or latency characteristics.

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?

Front-loaded with the core capability and batch limit, and nearly every clause carries information (data inventory, price definition, include semantics, sibling routing). The cost is a single sprawling sentence dense with nested parentheses, which makes it harder to scan than a bulletted structure would be.

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 the return-value burden and does so thoroughly: it names each returned section, the offer table's leading key, review-text limits, and unit-price quantiles. For a 3-parameter batch read tool, an agent has enough to call it correctly and interpret the result.

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. The description does add genuine meaning for the include enum values ('dupes' = cheaper same-spec products and what you give up; 'ladder' = one spec step up/down with price delta; 'checkup' = buying facts for one offer) and reinforces that include applies to every product, which goes slightly beyond the schema.

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 with explicit scope: 'Everything about one product, or up to 8 in one call,' then enumerates the returned data (specs with value frequencies, rating, review texts, offers, unit-price quantiles, price position, image link). It also draws boundaries against siblings by noting buy links, sellers, shipping and coupon terms 'come from get_offer.'

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 concrete routing advice: prefer a single batch call over parallel calls because 'their reads and price checks run together,' and send offer-level details to get_offer. The three include options are explained with what each returns. It stops short of saying when to use this versus search_products or show_products for discovery.

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