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

Annotations only declare readOnlyHint and openWorldHint, but the description adds substantial context beyond them: 36 results per page with a total-count field, available sort orders, and a cost model of $0.002 USDC per successful call via x402 on Base/Solana/Arc with failed calls uncharged. The payment/auth requirement is exactly the kind of behavioral disclosure that matters for an agent deciding to call.

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 resource and returned fields, then sort, then alternatives, then price — a sensible priority order with no filler sentences. The long semicolon-chained field enumeration is dense but every clause carries information an agent can act on.

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 re-explained, and the description still summarizes them, adds pagination size, sorting, cost and payment rails, and sibling routing. For a 3-parameter read-only search tool, nothing an agent needs to call 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 coverage is 100%, so baseline is 3, but the description adds meaning the schema lacks: it states the page size (36 per page) and that a total result count is returned, which tells the agent how to interpret and bound the 'page' parameter. The sort list is restated rather than enriched, and 'price' is less precise than the schema's price_low/price_high.

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?

Names a specific verb and resource ('Hepsiburada (Turkey) product search') and immediately scopes it with the returned fields and sort modes, so the agent knows exactly what it retrieves. The site/country qualifier distinguishes it from the many other marketplace siblings in the list.

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?

Explicitly routes two related needs elsewhere ('ecommerce_aliexpress when you need AliExpress product search', 'ecommerce_backmarket when you need Back Market refurbished-product search'), which is real alternative-selection guidance. It gives no explicit when-not-to-use and does not mention the nearest regional competitor, ecommerce_trendyol_turkey, so a small inference gap remains.

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