get_exchange_rate

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

Beyond the readOnlyHint annotation, the description adds important behavioral context: the rate is updated every minute, is for reference, and may not match actual transaction rates. This helps the agent set expectations, though it does not mention response formats or potential edge cases.

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 concise and well-structured: a single-sentence purpose, a one-line caveat, and an Args list. Every sentence adds value and the key information is front-loaded.

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 simple tool with three optional parameters and an existing output schema, the description covers all necessary aspects: what it does, how to use it, parameter meanings, and a critical limitation. It is complete for selection and invocation.

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 schema has 0% description coverage, but the description fully compensates. It explains base and quote currencies, their allowed values and defaults, the meaning '1 base = ? quote', and the ISO 8601 format for date_time, along with the behavior when omitted.

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 clearly states the tool queries the KRW-USD exchange rate with the verb '조회한다'. It specifies the resource (exchange rate) and the currency pair, distinguishing it from sibling tools that handle stocks, orderbooks, or trades.

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 explains that the rate is a reference display rate updated every minute and may differ from actual transaction rates, implying it is for informational use rather than real transactions. However, it does not explicitly name alternative tools or provide a clear 'when not to use' beyond the caveat.

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