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

With no annotations provided, the description shoulders the transparency burden. It discloses the 403 error behavior for low-tier users and specifies the return format (JSON array with listed fields). It does not state explicitly that it is read-only, but '行情数据' implies a data retrieval operation.

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: purpose, access requirement, parameters, and returns are all covered in a concise block. No redundant text or 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?

For a simple data query tool, the description provides the essential context: what it does, access restriction, parameters, and output fields. The output schema exists, so return fields are redundant but harmless. It lacks only minor details like pagination or field definitions, but those are covered by the schema.

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%, so baseline is 3. The description's parameter list merely repeats the schema's descriptions (symbol example, date format, and the trade_date mutual exclusivity). It adds no new meaning 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 the tool provides '融资融券明细' (margin trading details) as market data. The verb '明细' and resource are specific and distinct from sibling tools, though it does not explicitly call out alternatives.

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 mentions the PRO/PRO+ subscription requirement and that lower tiers return 403, which is a prerequisite/context. However, it does not explicitly state when to use this tool versus alternative data endpoints or provide exclusionary guidance.

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