lotto_results

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

The description adds significant behavioral context beyond the annotations: it explains that the rank is server-calculated, that the default 14-day window leads to '내역 없음' for older rounds, that the site caps queries at 3 months, and that the actual search window is returned in the `window` field. This discloses pitfalls and internal behavior that annotations do not cover.

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 front-loaded: it states the purpose first, then immediately addresses the critical nuance about `round_no` and the search window. Every sentence contributes unique information, with no redundant phrasing or filler.

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 read-only query tool with two optional parameters, an output schema, and annotations indicating safety, the description covers the essential user-facing behavior: the default window limitation, the workaround via `round_no`, and the site's hard limit. It also references the return field `window`, making the tool's behavior fully understandable for an agent.

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%, but the description compensates by explaining the semantic effect of `round_no` (expands the search window) and `days` (default 14, can be insufficient). It adds meaning beyond the schema's basic type and range descriptions, clarifying how parameters interact with the site's constraints.

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 opens with a specific verb and resource: '구매 내역과 당첨 결과를 조회한다' (queries purchase history and winning results). This clearly states the tool's function and distinguishes it from siblings like lotto_status, lotto_draw, and lotto_buy_precheck, which focus on different aspects.

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 provides clear context for when to use the tool and how to adjust parameters: passing `round_no` expands the search window to the site's 3-month limit, while the default 14 days may miss past rounds. However, it does not explicitly mention alternatives or exclusion criteria relative to sibling tools, so it falls short of a 5.

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