housing_affordability_calculate

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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), so the description's job is to add context — and it does: it discloses that the return is a scenario summary rather than a full monthly amortization table, and that results are arithmetic only with no product/approval judgment. It stops short of mentioning determinism or any rate-limit/size caveats, but the added context is meaningful.

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?

Three compact sentences: what it computes, what it returns, and what it does not do. The scope statement is front-loaded and nothing is redundant or padded.

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 deeply nested scenario object with no output schema, the description gives the essential shape of the answer (scenario summary, not a monthly table) and the interpretive limits (not an approval determination). It could say more about how many scenarios are compared or the units of the result, but an agent has enough to call it correctly.

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 100% and there is effectively one nested 'scenario' parameter, so the schema already documents every field including units and percentage conventions. The description adds only a high-level mapping (budget/cash/costs/LTV/DSR) to the nested inputs, not new per-field meaning, so the baseline 3 applies.

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 computation: an arithmetic comparison of affordable purchase price given monthly payment budget, cash, costs, and assumed LTV/DSR. This is clearly distinct from profile/notice/candidate siblings, though it never names the closest calculators (housing_loan_calculate, housing_finance_calculate) to sharpen the boundary.

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 closing sentence gives a useful when-not boundary ('실제 상품·승인 여부는 판단하지 않습니다'), telling the agent this is a planning estimate, not an approval check. However, no alternative tool is named and there is no explicit 'use this when…' routing, so the agent must infer when to prefer it over the other calculate tools.

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