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

With no annotations, the description must carry the full burden of behavioral disclosure. It mentions 'Browser-based tool' and automatic size classification, but does not explain how the tool accepts input (given zero schema parameters), whether it requires user interaction, or what output format to expect. This leaves important behavioral traits unclear.

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 extremely concise: one short sentence covering function, components, and an algorithmic trait. It is front-loaded with the core purpose and contains no 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?

For a zero-parameter browser-based tool, the description is minimally viable: it states purpose and output. However, it lacks guidance on how an agent should invoke or interact with a browser-based tool, or any caveats (e.g., region-specific fees, required user inputs). The 'browser-based' note adds some context but is insufficient for full completeness.

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?

The schema has zero parameters, so the baseline is 4. The description conceptually names the main inputs (FBA fees, storage fees, shipping fees) and notes automatic size classification, which adds meaning beyond the empty schema. Since there are no formal parameters, this is adequate.

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's function: calculating profit from FBA fees, storage fees, and shipping fees, with automatic size classification. The verb '計算' (calculate) is specific to a resource, and it distinguishes itself from siblings like amazon-acos-calculator by focusing on total profit rather than a single metric.

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?

There is no explicit guidance on when to use this tool versus alternatives. It does not mention any alternatives, exclusions, or prerequisites. The only implicit signal is that it is for profit calculation involving FBA costs, but that's not enough to guide selection among the many calculator siblings.

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