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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds genuinely non-obvious behavior: API-style billing where listing plugins charge one unit per result page fetched, which materially affects how an agent should size max_results.

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 tight sentences, front-loaded with the verb and resource, then return shape, then controls, then cost. No filler and nothing repeated unnecessarily.

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?

No output schema exists, but the description compensates by enumerating the returned product fields and the JSON format. Combined with full schema coverage of all 7 params and the billing note, an agent has what it needs; only cross-sibling selection guidance is absent.

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%, with per-parameter descriptions including defaults and enum-like sort values, so the schema carries the burden. The description only restates sort/min_price/max_price/max_results at a high level and adds no format or edge-case detail 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+resource ('Searches Walmart for `query`') and enumerates the exact return fields (name, price, wasPrice, rating, reviewCount, brand, seller, availability, image, url), which immediately distinguishes it from amazon_search/ebay_search/google_shopping siblings on the same platform-search axis.

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 usage context: sort with `sort`, narrow with `min_price`/`max_price`, and gather up to `max_results` across pages, plus a cost-driven caveat to 'keep max_results modest'. It does not, however, say when to prefer this over the sibling marketplace searches.

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