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

With no annotations, the description carries the burden. It explains the expression grammar and available factors, which clarifies behavior, but it does not state what the tool returns or its operational characteristics such as ordering and limits.

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 purpose, then gives a useful example and field list. The field enumeration is long but earns its place for a domain-specific expression builder.

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, so return values need not be described. Still, the orderby and limit semantics are left to inference, and with many ashare sibling tools, explicit routing would improve completeness.

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 required expr parameter is well explained with syntax, an example, and common field names. However, limit and orderby have zero schema description and are not addressed, so secondary parameters remain underspecified.

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 identifies a factor-screening tool for A-share stocks ('因子选股（量化筛股）') and gives a concrete trigger intent ('筛选/选股/符合条件的股票'). It does not name sibling tools it is not, so it falls short of full differentiation.

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 last sentence explicitly tells the agent when to invoke this tool: when the user asks to filter or find qualifying stocks. There is no explicit when-not-to-use or named alternative, but the trigger condition is clear.

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