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

Annotations already cover read-only, idempotent, non-destructive, closed-world behavior. The description adds genuinely non-structured context: the windows are fixed, and this is the unique source for per-product click/EPC/conversion metrics. It doesn't mention result size limits or pagination beyond the schema's limit cap.

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, zero waste, with the critical constraint (fixed windows, no period) front-loaded ahead of the alternative-tool routing.

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?

For a read-only ranking tool with no output schema, the description gives scope, metrics, and routing guidance. It could say more about what the ranked rows contain (e.g., which fields per product or how the 7- vs 30-day views are presented), but nothing needed to invoke it correctly is missing.

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%, including the note that sort_by applies to the 30-day window and the full marketplace enum values. The description only restates the metric names already in the enum, so it adds little beyond the schema — baseline 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?

States a specific verb+resource (product ranking) with explicit scope (fixed 7- and 30-day windows) and the metrics covered. It also distinguishes itself from the sibling painel_get_products_by_period by name, so an agent can route without opening either schema.

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?

Explicitly says the tool does NOT accept a custom period and names the alternative for that case (painel_get_products_by_period, with an example like 'mês passado'). It also flags itself as the only source for per-product clicks/EPC/conversion, which tells the agent when this tool is mandatory.

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