Get KRW/USD exchange rate

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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive behavior. The description adds valuable behavioral context beyond that: the rate refreshes once a minute, validFrom/validUntil bound the quote window, the rate is indicative and may differ from the settled order rate, and a 404 error is possible. No contradiction exists.

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 compact yet information-dense. It is front-loaded with the core purpose, then covers usage, parameters, return fields, caveats, and errors without redundancy. Every sentence adds value.

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 four-parameter read tool with an output schema, this description is exceptionally complete. It explains the return field semantics, the time-window behavior, the indicative-rate caveat, and error conditions. Nothing an agent needs to call it 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 coverage is 100%, so the schema already documents parameters well. The description adds useful semantic value beyond the schema, especially the example 'base='USD', quote='KRW' gives won per dollar' and the clarification that date_time is optional and omitted for the current rate.

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: 'Get the KRW <-> USD exchange rate, refreshed once a minute.' It clearly identifies the operation and the unique data it returns, distinguishing it from the many market-data and order sibling tools.

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?

It explicitly advises when to use the tool: 'Use this to convert between the KRW and USD figures that holdings and orders report separately.' This gives clear context and prevents confusion with other quote/price tools, even though no alternative tool is named.

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