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

With no annotations, the description carries the full burden and does so: it discloses the tool is a paid feature requiring a Key at Standard tier (¥29.9) or above, states the failure mode that English enum values return empty results, and clarifies the static/manifest nature. Auth requirements and silent-failure semantics are both surfaced.

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 purpose followed by routing, constraint, and pricing warnings separated by emoji markers, which aids scanning. Slightly repetitive since the Chinese enum values echo the schema, but no sentence is wasted.

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?

Complete for a static listing tool: purpose, trigger, alternative, enum constraints, and pricing/auth are all covered, and an output schema exists so return values need not be described.

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 coverage is already 100%, so baseline is 3; the description adds real value by warning that category/kind accept only Chinese enum values and that English input yields empty results, plus enumerating category and kind values beyond the schema's abbreviated lists. It stops short of a full accepted-value list, so it is not a 5.

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 (量化因子库) with concrete scope (88 factors, 50 screening entries, 22 preset combos) and clearly scopes it as a static manifest, explicitly contrasting with ashare_screen for actual stock picking. An agent can distinguish it from every sibling without opening a schema.

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 an explicit trigger ('有哪些因子/因子库/选股因子/因子分类') and an explicit alternative with its condition ('要用因子实际选股，用 ashare_screen'), covering both when-to-use and when-not-to-use.

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