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

Beyond the read-only and idempotent annotations, the description adds critical behavioral context: the tool does NOT calculate, the agent must perform arithmetic, the as_of date bounds the data's validity and must be reported, and the effective loan limit is the smaller of LTV and DSR. It also warns that later revisions are not reflected. This far exceeds annotation coverage.

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 dense but well-structured with bold markers and asterisked caveats. Every sentence carries actionable information—calculation division, as_of handling, min-rule, exclusions, and honesty instructions. It is front-loaded with the core purpose and then layers critical caveats in a scannable format.

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?

With an output schema present, the description doesn't need to detail return values, but it still references how_to_calculate and explains post-processing rules. It covers all necessary operational context: when to call, what to do with the result, how to handle date-sensitive data, and what is out of scope. Nothing needed 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?

The input schema has zero parameters, so the baseline is 4. The description correctly focuses on output semantics and usage instead of parameter details, which is appropriate since there is nothing to parameterize.

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 states a specific verb and resource: it provides current mortgage regulation figures (LTV, DSR, stress rate, regulated areas, price caps). It directly distinguishes itself from siblings like get_apartment and search_properties by framing the tool as a regulatory-facts provider, not a property or transaction data source.

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 gives explicit call signals with example questions ('5억 아파트 사려면...', '연봉 5천에...') and explicitly says to call this tool first. It also states what is not covered (취득세·중개보수) and instructs the agent to admit lack of knowledge when data is absent, making when-to-use and when-not-to-use clear.

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