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

With no annotations, the description carries the full burden and does it: it declares the tool read-only, discloses that it is a paid feature gated to the ¥99 professional tier, explains the exact rule behind is_limit_up/is_limit_down, and warns that mode=stock is current-day only. These are exactly the traits an agent cannot get from schema or annotations.

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?

Purpose and trigger examples are front-loaded, then mode semantics, then output fields, then constraints. Dense but organized; the field-by-field enumeration (up_px/down_px/hprice/lprice/open_px/preclose_px) is somewhat redundant given an output schema exists.

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 3-parameter read tool with an output schema, the description covers trigger conditions, mode selection, date requirement, access tier, and read-only safety. An agent has everything needed to call it correctly without follow-up.

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 still adds value by spelling out that mode=stock is minute-level tick data, stock-history is second-level, volume is a single point, and that date must be a real trading day — nuance the terse schema strings do not convey.

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: intraday call-auction (集合竞价) data for an individual stock, including limit-up/limit-down touch detection. The three modes and the derived flags (is_limit_up / is_limit_down) make it clearly distinct from generic siblings such as ashare_minute or ashare_quote.

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 concrete user phrasings that select this tool ('竞价分时 / 竞价怎么走的 / 哪些票竞价就涨停了') and explicitly routes history requests to mode=stock-history with a required date. It never names a sibling tool as the alternative for the non-auction minute data case, so it stops short of full when/when-not coverage.

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