ETF基本面与估值：获取ETF的市盈率PE、PE分位、市净率PB、PB分位、股息率、ROE等估值与基本面关键数据

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

No annotations are provided, so the description carries full burden. It describes what data is retrieved but lacks behavioral details: it doesn't specify data freshness (e.g., real-time vs. delayed), rate limits, authentication needs, error handling, or output format. For a data retrieval tool with no annotation coverage, this is a significant gap in transparency.

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 sentence that efficiently lists the key metrics, but it's repetitive with the title and could be more front-loaded. It wastes no words but lacks structural clarity (e.g., not separating purpose from details). It's adequate but not exemplary in conciseness or organization.

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's moderate complexity (1 parameter, no annotations, but with an output schema), the description is partially complete. It specifies the data retrieved, which is helpful, but since an output schema exists, it doesn't need to explain return values. However, it misses behavioral context (e.g., data sources, limitations), making it just adequate for basic use.

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 description coverage is 100% (the 'query' parameter is fully described in the schema as 'ETF基金代码或ETF基金名称'), so the baseline is 3. The description adds no additional parameter information beyond what's in the schema—it doesn't clarify format (e.g., code syntax), validation rules, or examples. Thus, it meets the minimum viable level without enhancing parameter understanding.

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 doesn't mention when to choose etfFunAnalysis over etfBasicInfo, etfLatestPrice, or other ETF tools, nor does it differentiate from stockFunAnalysis or sectorFunAnalysis for non-ETF assets. Usage is implied by the tool name and description but lacks explicit context or exclusions.

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