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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only mentions 'Browser-based tool' and support for 10 cities, but fails to explain how the tool operates, what inputs are required, what data sources are used, or any limitations. This is insufficient for a tool with zero 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 very concise, consisting of a single sentence plus a parenthetical note. Every part contributes value: the 10-city support and instant comparison are useful differentiators, while 'Browser-based tool' is somewhat redundant but not harmful. It is efficient and easy to scan.

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 calculator tool with no schema, no annotations, and no output schema, the description is incomplete. It does not specify which 10 cities are covered, how the simulator is invoked or used, whether user input is needed, or any limitations such as rate year or data source. This leaves the agent with insufficient context to confidently select and use the 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 input schema is empty, so the baseline is 4 per the rubric. The description adds no parameter information, but none is needed since the tool accepts no parameters. It does mention city coverage and comparison, which are capabilities rather than parameters.

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 title '国民健康保険シミュレーター' plus description '主要10都市対応。自治体間の保険料比較も一瞬' clearly identifies this as a National Health Insurance premium simulator with support for 10 major cities and inter-municipality comparison. This differentiates it from sibling calculators like resident-tax-calc or social-insurance-calc, though it does not explicitly name alternatives.

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 phrase '自治体間の保険料比較も一瞬' implies the tool is useful for comparing premiums across municipalities, providing some context on when to use it. However, it does not explicitly state when not to use it or mention alternative tools such as resident-tax-calc or social-insurance-calc, leaving the guidance implied rather than explicit.

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