realestate.rental_yield

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is known. The description adds useful behavior beyond annotations: output is a percentage string, amounts are KRW-unit strings, rounding uses HALF_EVEN by default, and net can be negative when expenses exceed rent. It does not describe error handling or edge cases like zero price, but the core calculation behavior is well disclosed.

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?

Front-loads purpose and formulas, then adds rounding defaults, negative-net behavior, and a misuse example. Every sentence provides actionable information; there is no redundant or filler text.

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 read-only, idempotent calculator with an output schema, the description supplies all needed context: formulas, input units, rounding defaults, sign behavior, and a common mistake to avoid. Nothing essential for correct invocation is missing.

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 0%, so the description must carry the burden. It defines the roles of annual_rent, property_price, and annual_expenses in the formulas, states that amounts are 원 단위 문자열, and explains rounding (default HALF_EVEN) and decimals (default 2). It also covers yield_type via the gross/net formulas and warns about monthly-to-annual conversion, fully compensating for the empty schema descriptions.

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?

States a specific verb and resource ('임대수익률을 백분율(%) 문자열로 계산한다') and immediately distinguishes the two yield types with explicit formulas. An agent can tell exactly what it computes and how gross differs from net without opening the schema.

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?

Explains gross vs net behavior and gives a concrete misuse example ('월 임대료를 연 환산하지 않고 annual_rent 에 입력'), which guides correct input preparation. It lacks an explicit 'use this instead of X' clause, but there is no direct sibling alternative for rental yield, so this is close to complete.

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