ETF基本信息：获取ETF基金的规模、费率、跟踪误差等基本信息关键数据与解读

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions retrieving '关键数据与解读' (key data and interpretation), which implies a read-only operation, but does not specify details like data freshness, rate limits, authentication requirements, or error handling. For a tool with no annotations, this leaves significant behavioral gaps.

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, efficient sentence that directly states the tool's purpose without unnecessary words. It is front-loaded with the core function, though it could be slightly more structured (e.g., separating data retrieval from interpretation). Overall, it earns its place with minimal waste.

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 tool has an output schema (which likely covers return values), no annotations, and a simple input schema with full coverage, the description is moderately complete. It clarifies the type of data retrieved but lacks behavioral context and usage guidance. For a basic read operation, it meets minimum viability but has clear gaps in transparency and guidelines.

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 has 100% description coverage, with the parameter 'query' documented as 'ETF基金代码或ETF基金名称' (ETF fund code or ETF fund name). The description does not add any additional meaning beyond this, such as format examples or validation rules. With high schema coverage, the baseline score of 3 is appropriate.

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?

Tautological: description restates name/title.

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. It does not mention when to prefer this over other ETF-related tools (e.g., 'etfLatestPrice' for price data, 'etfPerformance' for performance metrics) or general fund tools like 'fundBasicInfo'. Usage is implied by the title and description but not explicitly stated.

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