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

With no annotations, the description carries the full behavioral burden and does disclose useful traits: 只读查询 (read-only), 交易时段内实时 (real-time only during trading hours), and 免费工具（无需 Key）. It also warns that data is an array with data[0] as latest. It does not mention rate limits or pagination, keeping it short of 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?

The core purpose and trigger are front-loaded, followed by structured ⚠️ warnings. Dense but each warning carries actionable content (array shape, field name collision with /v1/snapshot, excluded fields). Slightly heavy on markers but nothing is pure filler.

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, yet the description still helpfully clarifies the data array ordering and the turnover field name. Combined with the sibling routing and read-only/free/real-time notes, an agent has enough to call it correctly; only edge behaviors like throttling are unaddressed.

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%, and the single code parameter is fully documented in the schema (market-prefixed formats like sh600667/sz000001/hk00700). The description's extra field hints (data[0].last, turnover) describe output usage rather than parameter meaning, so the schema does the heavy lifting — baseline 3.

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 specific verb+resource (real-time quote snapshot) and enumerates the 8 returned fields (现价/开高低/成交量/成交额/换手率). It also explicitly distinguishes itself from ashare_snapshot, ashare_kline, and ashare_orderbook, so an agent can route 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 the exact trigger ('用户问某股票现在多少钱/什么价用这个') and names three alternatives with the condition that selects each (valuation/market cap → ashare_snapshot, history → ashare_kline, order book → ashare_orderbook). When/when-not and alternatives are all explicit.

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