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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and external-network behavior are covered. The description adds that results are normalized and then derived into a snapshot, which is useful context, but it does not describe sampling behavior, pagination, or what the aggregation is based on beyond 'normalized product 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?

A single front-loaded sentence with no filler, stating the input (query) and the returned artifact. It is efficient, though borderline terse given there is no extra guidance to justify a 5.

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 the description need not enumerate snapshot fields, and coverage of the parameters lives in the schema. The only real gap is the absence of usage routing against shop_app_search, which keeps it from being fully complete.

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% and all five parameters (limit, query, on_sale, in_stock, deep_search) are documented in the schema, so the description adds no parameter-level meaning. This is the expected baseline when the schema does the heavy lifting.

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 clear verb (Searches), resource (Shop.app), and a distinct output shape (derived market snapshot from normalized results), which differentiates it from the plain shop_app_search sibling by implying aggregation rather than raw listings. It stops short of explicitly contrasting with that sibling, so a 4 rather than a 5.

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?

The phrase 'derived market snapshot' implies the tool is for aggregate/analytical questions rather than product lookup, and the sibling set (shop_app_search, shop_app_product) makes the alternative inferable. But there is no explicit when-to-use / when-not statement or named alternative.

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