Latest draw

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

Annotations already declare readOnly/idempotent/openWorld, and the description goes well beyond them: freshness lag, the meaning of prizes_pending ('that does not mean nobody won'), a hard rule never to fabricate missing numbers, precedence of official announcements, and disclosure that the `more` links point to an ad-bearing third-party site. That is unusually rich behavioral context for a read-only tool.

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?

Payload contents are front-loaded in the first sentence, followed by source, timing caveats, and the ad disclosure in a logical order. It runs long as a single dense paragraph and repeats the advertising disclosure bilingually, which is slightly redundant but defensible for a Chinese-language audience.

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?

There is no output schema, so the description has to describe return values, and it does: field-by-field payload, the `more` links, and the prizes_pending edge case. Combined with the freshness timeline, an agent has everything needed to call it and interpret the result correctly.

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% and the game parameter already lists every accepted id, Chinese name, and the retired games with their history end date. The description adds no further meaning about the parameter, 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?

States a specific verb+resource ('Latest official draw of a Taiwan Lottery game') and enumerates exactly what comes back: period, date, winning numbers in two orders, special/second-zone number, star-lottery digits, super number, and the prize table. The word 'Latest' plus the fixed enumerated payload separates it cleanly from get_draw (which an agent would expect to take a period argument) and list_draws.

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?

Gives explicit operational context: the official site publishes numbers at 21:30 and prizes at 22:00 Taiwan time, so before 21:30 the draw is normally missing and before 22:00 the prize table may be missing. It does not explicitly say 'use get_draw instead when you need a historical period', but the time-window guidance is clear and actionable.

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