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

With no annotations, the description carries the full burden. It discloses that the operation is read-only ('只读查询') and clarifies what data it does not provide (成分股/净值/持有人). It doesn't mention auth or rate limits, but for a read-only query with an output schema, this is adequate.

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 compact and front-loaded with the core functionality, includes a clear warning, and ends with a format note. Every sentence adds value, and the structure is easy to scan.

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?

With a single parameter, an output schema, and a description covering purpose, usage, read-only nature, and exclusions, the definition is complete for an agent to invoke correctly. Nothing essential is missing.

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%, and the parameter description already includes the format 'sh510300'. The description repeats this format, adding no new meaning beyond the schema. Baseline 3 is appropriate given the schema's completeness.

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 enumerates the tool's coverage (行情/规模/溢折率/资金流) and explicitly states it is for ETF queries. It differentiates from other endpoints by warning about constituent stocks/NAV/holders, making its scope unambiguous against siblings like ashare_quote and ashare_fund.

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?

It provides explicit routing ('用户问ETF时用这个') and a clear exclusion ('要成分股/净值/持有人请用对应端点'). This tells the agent exactly when to use this tool and when not, even without naming specific siblings.

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