jp_furusato_limit

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

Without annotations, the description carries the full burden. It accurately describes the calculation scope and input source, but doesn't disclose output format, rounding behavior, or edge-case handling. The core behavior is transparent, but additional details would improve confidence.

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 a single, well-structured sentence that begins with the action verb and includes the key condition and data source. No wasted words.

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?

Given the tool's simplicity (two numeric inputs, no output schema), the description sufficiently explains the purpose and input source. It doesn't explicitly state the return value, but 'calculate the limit' strongly implies the limit amount is returned.

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 input schema provides full descriptions for both parameters (taxable income and residence tax income levy), covering 100% of parameters. The description reinforces the 'residence_tax_income_levy' source but doesn't add extra meaning beyond 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 uses the specific verb 'calculate' and identifies the resource as the furusato-nozei limit with a clear condition (out-of-pocket cost stays at 2,000 yen). This clearly distinguishes it from sibling tools which are date utilities or ideco savings calculation.

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?

The description provides clear context: it's for calculating the donation limit using the residence-tax income levy from the annual tax notice. While it doesn't explicitly name alternatives, the sibling tools are unrelated, so there's no ambiguity about when to use this tool. No exclusions are mentioned.

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