Number frequency

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

Annotations only cover read-only/idempotent/open-world, but the description adds substantial operational context: data provenance (api.taiwanlottery.com), a non-real-time window (21:30 numbers, 22:00 prizes), the warning that a missing prize table means prizes_pending=true rather than no winner, and the ad-bearing `more` links. These are exactly the caveats an agent needs beyond the structured hints.

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 purpose is front-loaded and the independence disclaimer is well placed, but the text carries redundancy (the ads disclosure is repeated in English and Chinese) and includes prize-table/prizes_pending detail that reads as off-topic for a frequency-count tool with no output schema. Roughly a third of the text could be trimmed without losing agent-relevant meaning.

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 two-parameter read-only statistics tool with no output schema, the description covers what is returned (counts, gaps, hot/cold), per-game counting rules, data source, and freshness limits. The only oddity is the prize-table discussion, which does not belong to this tool's output and may briefly mislead about what fields to expect.

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 100%, so the baseline is 3; the description earns above that by explaining how counting differs per game — 大樂透 special numbers and 威力彩 second-zone numbers counted separately, 3星彩/4星彩 digits counted overall and per position. It restates last_n 1-200/default 30, which is redundant with the schema but harmless.

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 precise verb+resource statement ('Historical frequency of each number over the newest N official draws') and enumerates the exact outputs: count per number, draws since last seen, and most/least frequent. This is clearly distinguishable from siblings like latest_draw or get_draw, which return individual draws rather than aggregate frequency statistics.

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?

It gives clear usage context ('last_n 1-200, default 30') and a strong constraint on how to present results ('do not present these numbers as picks'), which is genuine guidance rather than mere description. It stops short of naming an alternative sibling or stating when to prefer get_draw/list_draws instead, so it is not a full when/when-not/alternatives treatment.

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