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

No annotations are provided, so the description carries the full burden. It does disclose the useful behavioral fact that results include both draw numbers and per-tier prize amounts, and 取得 implies a read-only lookup, but it says nothing about data freshness, caching, or whether periods must be past draws.

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 efficient sentence for the core purpose, but the leading bracketed keyword tag is front-loaded noise that adds no selection value and could mislead. Not wasteful in length, but the ordering does not put the actual purpose first.

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 2-param, no-required, read-only lookup with no output schema, the description covers the games, the resource returned (draw numbers + prize amounts), and the schema covers the period default. What is missing is only boundary guidance versus siblings.

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 only 50% (only period is described, as '期別，不填為最新'). The description compensates by mapping the bare enum values lotto649/superlotto638/daily539 to their real game names (大樂透、威力彩、今彩539), which the schema itself never explains.

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?

Names a specific verb (取得/fetch) and resource (開獎號碼與各獎項獎金) and enumerates the three games covered, so an agent can tell it returns lottery draw results. The bracketed prefix (台彩 發票 油價對獎) muddies this by throwing in invoice and fuel-price keywords that actually belong to sibling tools like life__check_invoice and life__get_fuel_prices.

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 statement of when to use this versus the sibling life__check_lottery or the invoice/fuel-price tools that the bracket references. The only usage signal is the description itself, leaving the agent to infer the boundary on its own.

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