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

Beyond the openWorldHint annotation, the description discloses what the tool returns (indices and descriptions, not raw population lists) and what it explicitly excludes. It also includes pricing context, adding useful operational transparency beyond the schema and 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 well-structured with clear sections for scope, included indicators, exclusions, and typical queries. It is somewhat longer than necessary but every section serves a purpose and the main function is front-loaded.

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 description is complete for a two-parameter lookup tool: it defines valid input scope, clarifies output semantics, enumerates exclusions, gives example queries, and includes pricing. Since an output schema exists, the description does not need to explain return values in further detail.

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 schema already covers both parameters in detail with 100% coverage, so the baseline is 3. The description adds value by reinforcing the requirement for a specific locatable point, providing typical query examples, and clarifying that city/district names alone are invalid inputs.

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 the tool queries surrounding population analysis for a specific Chinese address, with an explicit verb and resource. It also distinguishes itself by listing included indicators (population structure, residential density, business density) and excluding registry statistics and POI lists.

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 gives clear when-to-use context: valid for specific China-locatable points, not for city/district names or overseas addresses. It also provides negative scope (not household registration counts or POI details), but it does not explicitly name alternative sibling tools for those cases.

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