amazon_best_sellers

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

No annotations exist, so the description must carry the burden. It discloses the fields returned per product, which is a read-only listing operation, but omits rate limits, scraping fragility, error behavior for bad marketplaces/categories, and how many products per request are actually supported.

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 dense sentences, front-loaded with the resource and scope, with no filler. The heavy parenthetical enumeration of examples is slightly list-like but each item earns its place by teaching value formats.

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 listing return fields is somewhat redundant, and the description still leaves max_products semantics, pagination, and error handling undocumented for a 4-parameter tool with zero schema coverage and no annotations. Adequate but with clear holes.

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 0%, so the description must compensate, and it does for 'marketplace' (domain suffix with concrete examples) and 'categories' (URL slugs with examples like electronics, kitchen). However, 'max_products' is never explained and the 'ranking' narrative omits the 'most-wished-for' value present in the enum, leaving gaps.

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 specific resources (Amazon Best Sellers, New Releases, Movers & Shakers rankings), the scope (21 marketplaces), and the returned data shape. An agent can distinguish this from siblings like noon_products (a different retailer) 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?

Usage is implied (fetch Amazon ranking lists) and the description gives practical formatting guidance for marketplace and category values, but it never states when to prefer this over alternatives or any exclusions/prerequisites. No explicit when/when-not.

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