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

No annotations are provided, so the description carries the full disclosure burden. It does not say whether the content is static or time-sensitive, whether it reflects official sources, or what form the answer takes, leaving real behavioral gaps for a rules-lookup tool.

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?

A single compact sentence with the effective date front-loaded alongside the subject. Nothing is wasted, though the terseness trades away detail that could have added value.

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 annotations and no output schema, the description must stand alone. It identifies the topic and effective date but says nothing about scope, update cadence, or what the returned guidance includes, so it is only minimally sufficient for a zero-parameter info tool.

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 tool takes zero parameters, so there is nothing for the description to disambiguate at the parameter level. Baseline of 4 applies per the zero-parameter rule.

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 names a specific subject (Japan's tax-free new system taking effect 2026-11-01) and what it covers (refund procedure and points to note), which is enough to distinguish it from travel-logistics siblings like convert_currency or entry_requirements. It lacks an explicit verb (e.g. 'retrieve'), but the informational intent is unambiguous.

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 statement of when to call this tool versus alternatives such as entry_requirements or destination_info, nor any prerequisites or exclusions. The agent must infer usage purely from the topic label.

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