cn402_forex

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

The description indicates real-time operation and hints at pricing ('Price: unknown on Base (auto-paid in USDC)'), adding some transparency beyond no annotations. However, it does not disclose rate limits, supported pair details, or error behavior.

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 brief and front-loaded with purpose. However, the pricing line is tangential and may confuse; it could be restructured for clarity.

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 forex tool, the description covers basic purpose and a usage hint. It lacks details on return format, supported pairs beyond CNY, and whether rates are delayed. Output schema absence is not compensated.

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 is empty, but the description introduces a query param (`?pair=USDCNY`) with examples, which is critical information beyond the schema. This adds significant value despite the inconsistency.

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 tool name 'cn402_forex' and description 'Real-time foreign exchange rate' clearly indicate the tool provides forex rates. Mentioning support for major CNY pairs and majors further specifies scope. Sibling tools are for unrelated domains (bazi, fengshui, etc.), so differentiation is clear.

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 provides no guidance on when to use this tool versus alternatives, nor does it specify prerequisites or exclusions. While no sibling tools offer forex, usage context is not addressed.

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