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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds real context beyond that: the two report families, the ASIN/FNSKU/SKU grain, and an explicit scope limit on AWD fees. It stops short of describing pagination flow or date-window behavior, though the schema and output schema cover those.

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, no filler, and the scope boundary is front-loaded after the core purpose. The grain and variant enumeration are dense but each clause carries information.

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 14 well-documented parameters, full annotations, and an output schema, the description covers what is missing: what the tool returns, at what grain, and what it deliberately excludes. A brief note on how the two views differ in date semantics would close the remaining gap, but nothing an agent needs to call it is absent.

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 reinforces the monthly vs long-term split and the reporting grain, but the view-specific defaults and date constraints are already fully documented in the schema, so it adds little beyond it.

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?

Names a specific verb (returns) and resource (FBA storage fee report rows), states the grain it returns (ASIN/FNSKU/SKU), and enumerates both report variants. It also draws an explicit boundary ('This is FBA only; AWD fee reports are not exposed'), which distinguishes it from AWD siblings like get_awd_inventory.

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 makes clear which view yields which report family and implicitly steers the caller by naming what is not covered (AWD fees). However, it never names an alternative tool for adjacent needs (e.g. product fee estimates, financial events, profitability review), so routing vs siblings is left to the agent.

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