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

No annotations are provided, so the description must carry the behavioral burden. It discloses that this is a read-style data retrieval tool, the date range, currency unit, and default aggregation behavior, but it does not mention permissions, missing-year handling, or response structure.

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 two compact clauses with no wasted text, front-loading what is returned and following with the default partner behavior.

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 no output schema, the description appropriately explains that yearly quantity and amount in yen are returned across 2011–2025. The parameter schema is fully documented, so the main remaining gap is lack of detail about missing years or output shape.

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 all three parameters thoroughly. The description repeats the partner omission behavior that is already stated in the schema and adds no additional syntax or semantic detail, 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?

The description clearly states the tool returns yearly quantity and amount in yen for 2011–2025, sliced by flow, item, and partner country. It does not explicitly differentiate itself from siblings such as get_trade or top_partners, so it stops short of a 5.

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 provides one useful usage rule: omitting partner returns the world total. However, it gives no guidance on when to use this tool versus get_trade or top_partners, leaving sibling selection implicit.

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