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

Annotations already establish a safe read (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower, and the description adds genuine value beyond them: default descending sort by amount_total to surface high-value rows first, and the account/region-level scoping quirk that makes rows tenant-wide for any marketplace-scoped key. That scoping caveat is exactly the kind of behavioral context an agent would otherwise get wrong.

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?

Three sentences, front-loaded with purpose then filters then the scoping caveat. The final sentence is dense and slightly convoluted, but every clause carries operative information rather than filler.

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?

An output schema exists and annotations cover the safety profile, so the description's job is mostly scoping and expectation-setting, which it does. Pagination behavior is left to the schema, and no when-not-to-use guidance is given, but for a read-only filtered list this is close to 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 the schema already documents every parameter, including defaults, enums, and ranges. The description reinforces the filter set and explains why amount_total is the default sort, but adds no syntax or format detail beyond the schema, making the baseline 3 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 and resource ('Get FBA reimbursement records') and enumerates the filterable dimensions (date range, ASIN, reason), which clearly separates it from neighbors like get_returns and get_financial_events. It does not, however, explicitly name an alternative tool, so it stops short of full sibling differentiation.

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 implies usage by naming the available filters and the default sort, giving an agent enough to construct a query. It never states when to prefer this tool over related financial tools (get_financial_events, get_returns) or any prerequisites, so usage guidance remains implied rather than explicit.

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