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

With no annotations provided, the description carries the full burden. It discloses the tool's branching behavior (province passed vs omitted), the nationwide list returned in the default case, and the additional return of the next price-adjustment window date. It does not cover data freshness or error handling, but for a simple query tool the core behavior is transparent.

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?

Three short, well-organized sentences: purpose first, usage with example second, and the extra return value last. There is no filler or repetition, and the most decision-relevant information appears immediately.

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?

For a single-parameter query tool with no output schema and no siblings, the description explains the purpose, both invocation modes, and the additional returned date. Minor omissions such as price units or exact response formatting prevent a perfect score, but nothing critical is missing for correct invocation.

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 0% and the schema ony provides a property name, title, and default. The description compensates fully by explaining that the parameter accepts a Chinese province name, giving a concrete example, and describing what happens when it is omitted. This is exactly the parameter semantics an agent needs.

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 verb ('查询') and resource ('国内成品油价格') and enumerates the exact fuel types covered. The two execution modes (with or without province) are described unambiguously, so an agent can clearly identify what the tool does even without sibling context.

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 clear input-dependent usage guidance: pass a province name like '山东' for a single province price, or omit the parameter to get all 31 provincial prices. No alternatives are listed because there are no siblings, so no explicit when-not-to-use guidance is necessary.

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