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

Annotations already declare readOnly/openWorld/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely useful behavior beyond that: non-trading dates auto-walk back to the prior trading day, institution fields appear only when present, and the source is a keyless Eastmoney endpoint. Missing freshness/rate-limit context keeps it from 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 core concept before enumerating fields and aliases, and the bilingual query phrases earn their place for semantic routing. However, the middle is a dense run-on packing many alias strings and field lists, which is heavier than necessary.

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?

No output schema exists, so the description carries the return-value burden and does so thoroughly: EXPLANATION reason, close price, change %, buy/sell/net amounts in CNY, conditional institution_net_buy_cny/buy_seats/sell_seats, and a top-brokerages signal. An agent has enough to call it correctly.

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 both params (date format and limit range) are already fully documented. The description reinforces the date default/walk-back behavior but adds no syntax or format detail beyond the schema, so the baseline of 3 applies.

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 resource (Chinese A-share daily 龙虎榜 / dragon-tiger billboard) with a precise scope: stocks flagged for unusual price/turnover deviation plus seat-level buy/sell/net amounts. It further disambiguates from siblings like ashares_limit_up and ashares_turnover_ranking by naming the exact concept and its conditional institution-seat / top-brokerage additions.

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?

Provides concrete trigger phrases ('龙虎榜', 'dragon tiger list for a date', 'institution seat net buys') that route an agent cleanly. It stops short of explicit when-not guidance or naming an alternative sibling for the cases this tool does not cover.

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