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 known. The description adds meaningful scoping behavior: only paid/received reimbursements, recent window, categorized results, and a clear boundary against un-filed discrepancies. It doesn't describe pagination or return format, but that is minor for this simple read operation.

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 short sentences with no fluff. The core scope is front-loaded, and the sibling alternative is given in a compact second sentence. Every word earns its place.

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 one-parameter, read-only, list-style tool, the description plus schema is sufficient. It states what is returned (received reimbursements, by category), the time window, and the correct alternative. No output schema exists, but the tool's return shape is not complex enough to require further elaboration.

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% for the single optional days parameter, which is fully documented with default and max. The description's phrase 'recent window' loosely relates to days but adds no new syntax or format details, so the schema carries the weight and the 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?

The description clearly identifies the resource (FBA reimbursements), the status filter (already RECEIVED/paid), the window (recent), and the grouping (by category). It also distinguishes this tool from the sibling get_recoverable_reimbursements by stating that this one covers already-paid reimbursements only.

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?

It explicitly says when not to use this tool: for possible discrepancies not yet filed, use get_recoverable_reimbursements instead. That gives the agent a clear routing rule and prevents mis-selection among siblings.

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