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

The description discloses a key behavioral trait: '需要 PRO 及以上套餐（低档位调用返回 403）' (requires PRO and above, lower tiers return 403). It also notes the mutual exclusivity between trade_date and start/end dates ('与 start/end 二选一'). However, with no annotations, it doesn't cover other behaviors like rate limits, pagination, or default behavior when no dates are provided.

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 short and has a clear structure (title, auth note, Args, Returns). However, the Args block duplicates the schema property descriptions, so those lines don't earn their place. The Return fields section is useful, but overall conciseness is marred by redundancy.

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 and the description covers auth constraints, return format, and the trade_date/start_date exclusivity, it is reasonably complete. But it doesn't clarify optionality of all parameters or what happens if no date filter is used. For a straightforward data retrieval tool, this is adequate but not rich.

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 schema already provides 100% coverage of parameter descriptions, and the Args section in the description simply repeats the same text. No additional semantic value is added beyond the schema. The mutual exclusivity is already in the schema, so the description doesn't compensate or enhance 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?

The description clearly states the tool's resource: '指数成分与权重' (index constituents and weights). The Returns section lists relevant fields (symbol, trade_date, con_symbol, con_name, weight), which reinforces the purpose. It is distinct from siblings like index_daily, though it doesn't explicitly differentiate.

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 such as index_daily or concept_members. The only note is the PRO requirement and 403 error, which is a prerequisite rather than usage guidance. No exclusions or alternative tool mentions are given.

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