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

No annotations are provided, so the description carries the transparency burden. It discloses that the tool builds price history over time, implying persistence, but it does not clarify whether tracking has side effects, requires authentication, or what the response contains.

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 concise sentences, with the primary purpose front-loaded and no filler. Every phrase adds useful information about either the tool's function or how to provide input.

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 and no annotations, the description should explain return values and side effects, but it only explains input options. It also does not mention the `country` parameter or when to prefer this tool over closely related siblings like `price_history` or `price_alert`.

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?

The schema fully covers all three parameters, providing a baseline of 3. The description adds semantic value by framing 'asin' as 'exact product tracking' and 'query' as 'best-price discovery', which clarifies their intended use beyond the schema descriptions.

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 clearly states the tool tracks current product prices and builds price history, which is a specific action on a clear resource. It distinguishes between two input modes (ASIN vs. search query), though it does not explicitly differentiate itself from the sibling `price_history` tool.

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?

It provides explicit guidance on when to use an ASIN versus a search query, which is directly useful for invocation. However, it does not mention alternatives like `price_alert`, `price_history`, or `compare_prices`, so there is no comparison with sibling tools.

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