get_repeat_purchases

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

With no annotations, the description carries full burden for behavioral disclosure. It does not state whether the tool is read-only, what data is modified, authentication needs, or rate limits. The description only defines the metric without any operational context.

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?

The description is extremely concise (one sentence), but lacks structure—no separation of purpose, usage, or parameter details. It is not wasteful, but underspecification harms clarity.

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?

Given 2 parameters with 0% schema coverage and no annotations, the description is incomplete. It does not explain what each parameter does, default behavior, or how the output schema relates to the metric. The presence of an output schema does not compensate for missing parameter and usage info.

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 0% and the description does not mention parameters (days_back, marketplace) at all. It adds no meaning beyond the schema's bare property names, failing to explain how parameters affect repeat purchase rate calculation.

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 'Repeat purchase rate by ASIN (Brand Analytics)' clearly states the tool computes a specific metric (repeat purchase rate) for ASINs under Brand Analytics, distinguishing it from siblings like get_sales_and_traffic or get_market_basket.

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?

No guidance is provided on when to use this tool versus alternatives. Among 50+ sibling tools, there is no mention of prerequisites, constraints, or scenarios where this is preferred.

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