get_etf_option_expire_day

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

The annotation readOnlyHint=true already signals a safe read operation. The description adds value by disclosing the output fields (expiration date and remaining days), even though it says '等信息' (etc.) without specifying the complete return structure. This is useful context for an agent and does not contradict the 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 a single sentence, front-loaded with the action and resource, and contains no redundant words. Every part contributes to understanding the tool's purpose.

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?

This is a simple read-only tool with two well-documented parameters. The description covers the primary return fields but leaves some ambiguity about the exact return type/format and the precise meaning of 'expire day' (e.g., last trading day vs first day of expiry period). Given the lack of an output schema, a bit more detail would improve completeness, but it is adequate for the tool's simplicity.

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%: both 'cate' and 'month' have explicit descriptions. The tool description does not add meaning beyond the schema, such as the relationship between parameters or expected formats, so the baseline score of 3 is appropriate.

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 action ('获取' = get) and resource ('ETF 期权到期日信息' = ETF option expiration date information), and specifies the output contents (到期日, 剩余天数). This distinguishes it from sibling tools like get_etf_option_months, which likely return the list of available months rather than the expiration details for a specific month.

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 implies usage from its purpose but provides no explicit guidance on when to use this tool vs alternatives. Sibling tools such as get_etf_option_months or get_etf_option_daily_kline exist, but the description does not mention them or explain the distinction. It is not misleading, but it lacks clear when-to-use/when-not-to-use context.

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