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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=true, so safety is covered. The description adds genuine behavioral context beyond that: the FX conversion methodology, the accounting-basis mismatch caveat, and the per-metric/per-year row shape of the response. Not fully exhaustive (no mention of rate limits or caching), but substantial added value.

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-loaded with the core purpose, then structured Args/Returns/Examples/Errors sections. There is mild redundancy between the Args block and the already-complete schema descriptions, but the examples and error guidance earn their space.

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?

An output schema exists, so return-value explanation is not required, yet the description still summarizes the row shape and the FX/caveat payload. Combined with explicit error handling and usage exclusions, nothing an agent needs to call this correctly 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 100%, so the schema already documents each parameter including accepted identifier formats and the metrics enum. The Args block restates these with examples but adds no semantics the schema lacks. 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 verb (compare), the exact resources (annual financial statements of a Korean and a US listed company), the data sources (OpenDART/K-IFRS and SEC EDGAR/US-GAAP), and the normalization applied (KRW→USD via Fed H.10 rates). This clearly separates it from the single-market siblings get_dart_financials and get_edgar_financials.

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?

Gives explicit exclusions ('Don't use for quarterly data (annual only) or non-KR/US companies') and routes the agent to fallback tools (search_dart_company / search_edgar_company) when a name is unknown. The example query also shows a realistic invocation condition.

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