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

With no annotations, the description carries the burden and does well: declares read-only (只读查询), states that a single call returns the full universe with no pagination, and that an empty `date` means realtime while a historical date must be a real trading day or returns empty. It does not mention auth, rate limits, or freshness/latency of the realtime snapshot, which keeps it below a 5.

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?

Front-loaded with the purpose and routing question, then mode semantics, then caveats — a sensible order. It is dense and information-rich, but the enumeration of every returned field (reason/seal_amount/main_net/...) is partly redundant given an output schema exists, so a little could be trimmed.

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?

An output schema exists, so return values need no prose explanation; what remains — scope, mode choice, realtime vs history, empty-result behavior, no pagination, and the sibling escape hatch — is all present. Nothing an agent needs in order to call it correctly 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%, so baseline is 3, but the description adds genuine semantics: it defines `auction` operationally (09:25 定盘即封涨停, and explicitly excludes names that touched limit-up intraday but opened before the close) and clarifies `date` empty = realtime vs. historical trading-day requirement. The long field list for `limit` is mostly return-value detail rather than parameter meaning.

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?

States a concrete verb+resource: 当日涨停个股 with 涨停原因 and 资金面, and immediately names the sibling it is not (梯队结构/板块主线 → ashare_review). An agent can distinguish it from ashare_auction and ashare_review without opening any schema.

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?

Gives explicit user phrasings that should route here ('今天哪些票涨停 / 涨停原因 / 封单多大 / 主力买了多少') plus explicit when-to-use-another rule pointing to ashare_review. It also spells out the selection condition between its own two modes rather than leaving it to inference.

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