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

The description discloses that results are candidates with typical estimates, not guaranteed figures, and that actual requirements need official confirmation. It also adds a minimum input constraint, which goes beyond the readOnlyHint annotation. No contradictions with annotations.

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 front-loaded with the core purpose, then systematically explains each parameter and its enum values with clear separators. Though long, every sentence is informative and necessary given the 21 total enum values.

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?

The tool has three enum parameters and no output schema; the description covers all input possibilities and even hints at return contents (amounts/subsidy rates) while adding caveats about verification. It could be more explicit about the exact return format, but is otherwise sufficient.

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 only provides short labels (品目, やりたいこと, 立場), while the description fully explains each enum value with Japanese translations and context (e.g., 'new-farmer' means starting soon or recently, 'machine' means buying/renewing machinery). This significantly enriches the schema.

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 that the tool returns candidate subsidies/grants/funds in Japanese agriculture based on audience, purpose, and crop, using a specific verb ('返す') and resource. However, it does not explicitly differentiate itself from sibling tools like search_articles or rice_advance_payment.

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 clear usage guidance: specify any of the three parameters with at least one required, and notes that amounts are estimates requiring verification. However, it does not mention when to prefer this tool over siblings.

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