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

Annotations already declare readOnly and openWorld, and the description adds genuinely new behavior: rich PA-API product results when a storefront is configured, otherwise deep-link cards plus catalogMatches. This explains the variable return shape, which is the main behavioral risk here; auth and rate-limit behavior remain unstated.

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 purpose, then return behavior, then the mandatory-parameter rule. The trailing 'OpenAPI: searchAmazon' pointer is terse but low-cost.

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 does the necessary work of explaining what comes back (products vs. deep-link cards vs. catalogMatches) and which parameters are non-negotiable. Remaining gaps are the semantics of the occasion/budget filters and result-count behavior.

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 57%, with q, locale, marketplace and styleTag documented. The description reinforces the mandatory marketplace/locale but adds nothing about the undocumented occasion and budgetBand enums or the limit cap, so it only marginally exceeds the schema baseline.

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 ('Search Amazon for romantic partner gifts') plus the downstream purpose ('build a recommendation or shopping list'). It is clearly distinct from wishlist/catalog siblings, though it never names an alternative explicitly.

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 context is implied by 'to build a recommendation or shopping list', and there is a hard directive to 'ALWAYS pass marketplace + locale'. However, there is no when-not guidance and no mention of when an agent should prefer get_catalog or resolve_product instead.

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