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

With only openWorldHint annotation, the description carries the behavioral disclosure burden. It clearly states that the tool returns only count-type indicators and explicitly excludes specific store names and coordinate distributions, plus it discloses pricing. It does not describe edge cases like version mismatch, but the schema already covers those details; no contradiction.

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 concise and well-structured: purpose first, then scope, exclusions, alternative tool, and example questions. The pricing block is compact and structured. No redundant or filler sentences.

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?

Given that an output schema exists and all parameters are fully described in the schema, the description provides sufficient context: scope, covered categories, non-returned data, alternative tools, typical questions, and pricing. It is complete enough for an agent to select and invoke this tool 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%, and all three parameters already have detailed descriptions in the input schema, so the baseline is 3. The main description adds category coverage and example queries but does not add new parameter-level semantics beyond what the schema provides.

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?

Description clearly states the tool queries regional POI macro count indicators (数量/密度/增长) and lists covered amenity categories. It explicitly distinguishes from detail tools by saying '不返回具体门店名称与坐标分布列表（明细请用 poi_data_*）', which differentiates it from sibling poi_data_* tools.

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 explicit when-to-use guidance for aggregate POI count questions and names the alternative poi_data_* tools for detailed store/coordinate lists. It also gives typical query phrasings ('某区综合医院数量、肯德基门店数量、超市数量TOP城市'), making selection straightforward.

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