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

No annotations are provided, so the description carries the burden. It discloses the T-1 data lag for the updown module, states that the tool is free and requires no Key, and warns that the updown module is deprecated for today's breadth. It doesn't describe the output format in detail, but the output schema exists and the key behavioral caveat is disclosed.

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 purpose, then lists type values, then gives usage triggers and the important caveat. It is dense but every sentence earns its place. The warning is a bit long but necessary for correctness.

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?

For a single-parameter tool with an output schema, the description covers the main usage trigger, the type values, the key caveat about T-1 lag, and the alternative tool. It doesn't explain the output schema's structure, but the output schema itself handles that. The only minor gap is not explaining what each type returns in detail, but the type names are self-explanatory.

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 has 100% description coverage for the single 'type' parameter, and the description adds meaning by listing the valid type values and their meanings (summary/trade/interval/technical/valuation/rotation). The description also reinforces the schema's warning about using ashare_changedist for breadth. This adds value beyond the schema.

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 this is a market-level overview tool with a specific verb ('画像' / profile) and enumerates the distinct type values (summary/trade/interval/technical/valuation/rotation). It also names the exact user queries that should trigger this tool, which distinguishes it from siblings like ashare_changedist and ashare_technical.

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 explicitly tells the agent when to use this tool ('用户问今天市场怎么样/大盘环境/风格轮动/估值分位用这个') and explicitly warns against using it for market breadth, directing the agent to ashare_changedist instead. It also notes the T-1 lag caveat, which is a clear exclusion condition.

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