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

With no annotations, the description carries the full behavioral burden. It usefully discloses what the result contains (cash dividend, last close, estimated yield) and that it is a future ex-dividend calendar, but it never states the read-only nature, whether results are paginated, or thresholds/limits, and no output schema backs it up.

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?

A single front-loaded sentence that packs the resource, returned fields, and filter into one line with no filler. It is appropriately sized, though the comma-chained clauses are dense rather than clearly structured.

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 query tool with no output schema and no annotations, the description does convey the returned data and the yield filter, which is the core need. However, with zero required parameters it does not explain what happens if code is omitted (all stocks?) or how the default days window behaves, leaving gaps an agent must guess at.

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%, so the schema already documents each parameter (code, days with default 30/max 120, min_yield). The description's '可篩最低殖利率' merely restates the min_yield parameter and adds no format or syntax beyond the schema, so the baseline 3 applies.

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 single sentence gives a specific verb+resource (查詢 Taiwan-listed stocks/ETFs future ex-dividend calendar) and adds the distinguishing data payload (cash dividend, closing price, estimated yield, min-yield filter). It is clear what the tool does, but it never names or contrasts with the many sibling dividend tools (get_tw_ex_dividend, get_tw_dividend, get_etf_dividends), so differentiation is left to inference.

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 statement of when to use this tool versus the surrounding siblings that all deal with dividends or ex-dividend data. The mention that it 'can filter minimum yield' hints at a use case but is not framed as guidance, and no exclusions or prerequisites are given.

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