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

Given only a minimal annotation (openWorldHint: true), the description carries the transparency burden. It discloses the scope of data by listing all indicators and exclusions, and implies temporal changes ('周期变化'). No contradictory statements; it effectively communicates what the tool returns.

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 long but well-structured: it front-loads the purpose, lists exclusions, enumerates indicators, and gives typical queries. It is not overly verbose and every sentence contributes, though some redundancy between 'not used for' and 'not include' could be consolidated.

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?

With an output schema present, the description doesn't need to explain return formats. It thoroughly covers scope, exclusions, examples, and edge cases (e.g., non-Chinese company names). For a complex tool with many sibling tools, this description is fully adequate.

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 100% for the two parameters, so baseline is 3. The description adds value by providing concrete examples (e.g., '中国比亚迪股份有限公司', '美国Tesla, Inc.') that clarify parameter formats and usage context, slightly exceeding the baseline.

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's purpose: to query cyclical changes in business activities related to investment and financing for a specific company. It lists explicit indicators (e.g., new external equity investment, new financing, SOE/listed company interactions) and distinguishes from siblings by excluding financing rounds and branch changes.

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 explicitly states what the tool is NOT for (financing rounds, branch setup), and provides typical query examples (e.g., 'Is BYD involved in new external equity investment?'). It doesn't name alternative tools but clearly scopes usage, making it easy for an agent to decide when to invoke it.

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