option_sse_expire_day_sina

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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the return shape (a two-element tuple of expiry time and remaining time), which is useful, but it says nothing about the data source (Sina), freshness, or exchange semantics.

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 short and front-loads the purpose in the first line. The remaining lines are docstring boilerplate (:param/:type/:return), which duplicates field names but stays compact.

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 simple read-only, three-parameter data-fetch tool with no output schema, the description covers purpose, the important parameter values, and the return tuple. The exchange parameter is thin, but the core contract an agent needs is present and annotations cover the safety context.

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 0%, so the description carries the burden. It documents trade_date with concrete expiry-month examples and symbol with '50ETF or 300ETF', which adds real meaning, but the exchange parameter is left as 'null' with no explanation of its accepted values.

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 names a specific verb+resource combination ('剩余到期时间' for a specified expiry month and product) and states what is returned (expiry time, remaining time). It is clear what the tool does, but it does not distinguish itself from sibling option_sse_* tools (e.g., option_sse_greeks_sina, option_sse_daily_sina), so an agent must infer the difference.

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?

There is no guidance on when to use this tool versus alternatives. The only usage-like content is parameter examples (expiry month values, 50ETF/300ETF), which concern inputs rather than tool selection or context of use.

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