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

Annotations already declare read-only, open-world, non-idempotent, and non-destructive behavior. The description adds valuable cost model details (default 1 credit, plan-dependent, repeated calls may charge again) and a data trust warning, both beyond annotations. It does not cover authentication needs or rate limits beyond cost.

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?

Four short sentences, front-loaded with purpose, then cost, cost repetition, and trust warning. No filler; each sentence addresses a distinct operational concern.

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?

For a read-only retrieval tool with no output schema and rich schema descriptions, the description covers purpose, cost, and data trust. It omits usage differentiation from siblings, but that is assessed separately; the core call context is otherwise 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%, so each parameter is documented in the schema. The description adds no parameter-specific meaning beyond the 'category' framing that maps to nodeIdPath; baseline 3 applies 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?

States a specific verb ('Retrieve') and resource ('product price distribution for a category'), making the tool's output clear. It does not explicitly name or distinguish against sibling tools such as amazon_market_rating or amazon_market_statistics, so it falls short of the highest clarity tier.

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?

Provides no when-to-use guidance, prerequisites, or alternatives. An agent must infer usage from the name and schema alone; no condition selects this tool over the many other amazon_market_* siblings.

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