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

Annotations only include openWorldHint=true, which is not a strong behavioral trait. The description adds significant behavioral context: it indicates the tool is read-only (queries a list) implicitly, and it explicitly scopes to single region ('不支持同时查多个地区') and to specific POI types. It also clarifies billing model: 'Not charged per POI store/row' and describes data unit as region × POI type, which is useful for usage. There is no contradiction with 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?

The description is moderately concise: two sentences, with the first giving a full functional summary and the second clarifying exclusions. It is front-loaded with the core purpose. However, the additional pricing JSON at the end adds a bit of structural clutter, but it is useful context. Overall, each sentence contributes value, no fluff.

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 the tool has an output schema, we don't need to explain return values. The description covers the core functionality, scope, exclusions, and billing. It has an openWorldHint, but no other annotations; it adequately describes single-region limitation and POI type candidate set. The complexity is moderate, and the description is complete enough for an agent to select and invoke it correctly, though it could add more on edge cases like unsupported regions.

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 adds value by clarifying the overall query purpose (input_text), indicating that gov_name and poi_type are for disambiguation and are extracted from input_text when absent, and showing how they relate to the query. It also states that poi_type is limited to a candidate set of the theme, which is not in the schema. This goes beyond the schema's bare descriptions, so a 4 is justified.

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 states it queries a list of life service and entertainment POIs within a specified administrative region, enumerating covered categories (e.g., beauty salons, repair, logistics, gyms, cinemas, entertainment venues). It explicitly distinguishes from counting tools by saying it does not answer statistical questions and points to '兴趣点数量指标' as an alternative, thus distinguishing from siblings that may count POIs.

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 description explains when to use this tool (for detailed POI lists in a region) and explicitly says '不回答这类设施的数量统计' and suggests using the quantity metric tool instead. It also provides typical query examples ('某区健身房分布、电影院列表、美容美发店有哪些'). However, it does not mention when not to use it beyond that, nor does it reference specific sibling names like 'poi_data_*' that might also return POI data, but it gives clear context for usage.

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