forex_rate

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

No annotations are provided, so the description carries the full burden. It discloses cost ($0.02/call) and free tier usage (50/50 today), which is helpful for behavioral understanding. However, it does not disclose whether the tool is read-only, any rate limits beyond the free tier, or the format of the response.

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 very concise, comprising a single line with category, Chinese term, pricing, and API URL. It wastes no words, but its brevity sacrifices completeness. The structure is clear and 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?

Given the lack of output schema and minimal description, the tool does not inform the agent about return format, currency code conventions (e.g., ISO 4217), or error handling. The description provides the API endpoint and cost but is incomplete for a reliable tool invocation without further assumption.

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%, with descriptions in Chinese for 'base' and 'target' (base and target currency). The tool description adds no additional parameter information beyond the schema, meeting the baseline expectation but not exceeding it.

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 provides the Chinese term '外汇汇率' implying foreign exchange rate, and the name 'forex_rate' is clear. However, it does not explicitly state that the tool retrieves current exchange rates between two currencies. The purpose is adequately implied but not explicitly defined.

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 offers no guidance on when to use this tool versus alternative tools like 'crypto_price' or 'stock_price'. No scenarios or exclusions are mentioned, leaving the agent to infer usage from the tool name alone.

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