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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds that the data is 'public' and tied to a merchant profile, which is useful scoping. It stops short of pagination or freshness details, so a 3 is appropriate given the lower bar set by annotations.

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?

Two sentences, no filler, and the core purpose is front-loaded before the routing hint. Every clause earns its place.

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 an output schema present, return format needn't be explained, and both parameters are fully documented. The description covers purpose, routing, and scoping, leaving only minor gaps like pagination behavior on a capped list.

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% – both handle and limit are documented in the schema, including the default 20 and max 50. The description only reaffirms that handle selects the profile and limit caps the result, adding no syntax beyond the schema. Baseline 3 for fully-documented params.

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 (Fetch), resource (public review items from a Shop.app merchant profile), and the lookup key (by handle). It explicitly distinguishes itself from shop_app_product_reviews and shop_app_shop, so an agent can route without opening any 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?

Names the two relevant alternatives and the condition that selects each: shop_app_shop for merchant details, shop_app_product_reviews for product reviews. The routing is explicit rather than implied.

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