获取外汇汇率

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions 'output standardized fields' but does not specify what those fields are, whether any authentication is needed, or if there are rate limits. It is a read-only operation by nature, but that is not explicitly stated, and the vague 'standardized fields' leaves much unexplained.

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 a single, front-loaded sentence that states the action and output in a compact manner. Every word earns its place, and there is no redundancy or filler.

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 one-parameter tool, the description is adequate but not complete. There is no output schema, so the description's phrase 'standardized fields' is insufficient to inform the agent about the return structure. It also lacks usage guidance relative to fx_history. However, the tool is simple, and no nested objects or complex behaviors are involved, so a moderate score is appropriate.

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 fully describes the single 'symbol' parameter, listing all supported currency pairs with 100% coverage. The description adds no parameter-specific detail beyond what the schema already provides, so it meets the baseline but does not exceed 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 clearly states the tool's function: retrieving real-time exchange rates for major currency pairs and outputting standardized fields. It distinguishes itself from sibling fx_history by explicitly saying '实时' (real-time), and from crypto/futures tools by its focus on FX.

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?

No guidance is provided on when to use this tool versus alternatives. Although the 'real-time' wording implies it is for current rates, there is no explicit mention of fx_history for historical data or any other exclusions. The description does not help an agent choose between fx_rates and the closely related fx_history sibling.

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