operator_top_brands

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

Annotations already indicate readOnlyHint=true, so the read-only nature is clear. The description adds value by explaining the return fields (est_units_30d, est_revenue_30d, asin count, buybox days) and the estimation methodology (weighted by buy-box share). No contradictions.

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 concise: two sentences that front-load the main purpose, provide concrete usage examples, and include an alternative tool reference. No wasted words.

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?

While the description covers the primary use case and return fields, it does not explain the many filter parameters (e.g., brand_contains, range filters). With no output schema, more detail on the response structure or pagination would help. Adequate for basic queries but incomplete for advanced filtering.

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 coverage is low (29%) with only 4 of 14 parameters described in the schema. The description does not elaborate on undocumented parameters like min_asin_count, brand_contains, or range filters. It only mentions the sort default (est_sales). This fails to compensate for the lack of 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 shows brands an operator sells most by estimated sales, with explicit example queries like 'what brands does this seller sell the most of'. It distinguishes itself from sibling tool operator_brands_by_competition.

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 explicitly says when to use (brand-level drill-down by sales) and when not (brand competition, directing to operator_brands_by_competition). It also provides specific query examples.

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