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

No annotations are provided, so the description carries full burden. It discloses the ranking basis (sales volume) and temporal scoping, which is useful. However, it does not mention whether it is read-only, authentication needs, pagination, or response format. The description is not contradictory but adds only moderate behavioral 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 a single, front-loaded sentence with no filler. It efficiently captures the tool's purpose and primary scoping without redundancy.

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?

This is a simple read-only tool with three optional parameters and no output schema. The description adequately conveys the core functionality and ranking logic. It could provide more detail on return fields or limitations, but given the low complexity, it is reasonably 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 all three parameters (limit, period, category) have individual descriptions. The tool description adds no additional parameter-level meaning beyond the schema, so the baseline score of 3 is appropriate.

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 uses a specific verb ('Get') and resource ('top-selling marketplace items') with clear scope ('ranked by sales volume in a given time period'). This distinguishes it from siblings like 'trending' or 'browse' by explicitly stating the ranking criterion and time window.

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 description clearly conveys when to use the tool (to retrieve top sellers by sales volume over a time period), providing clear context. However, it does not explicitly mention alternatives or when not to use it, such as comparing to 'trending' or 'marketplace_stats'.

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