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

With no annotations, the description carries the full behavioral burden. It usefully clarifies that results are authoritative official rankings rather than exploratory search results, but it does not disclose read-only status, pagination/limit behavior, return shape, or any access constraints.

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 front-loaded with the core purpose and then gives routing guidance. It is slightly repetitive in listing query phrasings such as ranking/leaderboard/top-N/chart/hot list, but the emphatic guidance is relevant for tool selection.

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?

The tool has four parameters, low schema coverage, no annotations, and no output schema. The description is complete enough for tool selection and routing, but it leaves parameter details and return-value expectations underexplained, which matters given the structured-field gaps.

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 low at 25%, so the description should compensate. It names source, period, optional snapshot date, and top-N sizing, but it does not explain the enum meanings, limit range/default, or date interaction beyond what the schema already shows.

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 states a specific verb and resource ('Return the authoritative AIGC_NEWS ranking board') and scopes it to source, period, and optional date. It clearly distinguishes this tool from search tools, which is exactly what an agent needs to select it.

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 explicitly says when to call this tool vs search alternatives: rankings, leaderboards, top-N lists, charts, hot lists, and 榜单 queries should use this tool, while search with scope='today' is for exploratory discovery. The exclusions and alternatives are stated directly.

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