option_sse_expire_day_sina

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safe read-only nature is covered. The description adds the return format (a tuple of expiration time and remaining time) and specific accepted parameter values, which is useful but does not go beyond what a simple read-only utility would imply. No contradictions detected.

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 compact and well-structured, following a clear docstring format with title, params, return, and rtype sections. Every line contributes necessary information. It is not overly verbose, though the opening sentence could be more action-oriented (e.g., 'Returns the remaining...') rather than a noun phrase.

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 tool with no output schema, the description covers the purpose, all three parameters, and the return type. It does not specify the unit of 'remaining time' (days vs. seconds) or mention the data source (SSE/Sina), but given the low complexity and supportive annotations, it is reasonably complete.

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 must compensate. It does so by providing docstring-style explanations for each parameter: trade_date with example values, symbol limited to '50ETF or 300ETF', and exchange noted as null. It also specifies the return tuple. The examples for trade_date contain a likely typo ('20203' instead of '202003') and the exchange value 'null' is ambiguous, but overall the description adds meaningful semantics beyond the schema.

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 that the tool provides the remaining expiration time for a specified expiration month and underlying (50ETF or 300ETF). This distinguishes it from sibling tools like option_sse_greeks_sina (which calculates Greeks) and option_sse_daily_sina (daily data). However, the description is a noun phrase rather than a specific verb+resource, which slightly reduces clarity.

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?

No explicit guidance is given on when to use this tool versus alternative option tools. The description only explains parameter meanings (trade_date, symbol, exchange) and does not mention any exclusions or alternative tools. Since the sibling list contains many option-related functions, this lack of differentiation makes it hard for an agent to know when this is the right choice.

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