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

Annotations already mark this read-only/non-destructive, covering the safety profile. The description adds meaningful context beyond annotations: paid access is required, data is weekly, and it merges retailer and mapped Amazon ASIN series. It does not mention pagination or rate limits, but those are less critical for a read-only history endpoint.

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 with front-loaded 'PAID.' and dense information about scope, merged series, metrics, and time range. The only minor blemish is the slight redundancy between 'PAID.' and 'Requires a paid plan.'

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 3 parameters and no output schema, the description covers what will be returned, the time horizon, and the access cost. It does not explicitly describe response structure, but the schema covers parameter constraints and the payload is straightforward for a price-history endpoint.

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 the baseline is 3. The description adds useful domain context such as the merged Amazon series and metric names, but it does not add new parameter-level semantics beyond what the schema already provides for weeks and product_id.

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+resource: returns weekly price history for a retailer product by SKU/ID. It also specifies the merged Amazon ASIN series and the metrics included (Buy Box, lowest 3P-new, list price, sales rank), clearly distinguishing it from the sibling get_amazon_asin_price_history.

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?

Clearly establishes the tool's scope and the paid-plan prerequisite, so an agent knows when this tool is a candidate. It does not explicitly name alternatives or exclusion cases such as when to choose get_amazon_asin_price_history instead, leaving some routing to inference.

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