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 clearly indicates this is a listing operation (read-only implied) but does not disclose the output format, pagination, or whether the list could be empty. For a zero-parameter tool, it is adequate but lacks the richness that annotations would normally 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?

Two sentences with no fluff. The first packs all essential output details, and the second gives a direct usage pointer. Information is front-loaded and every sentence earns its place.

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 tool with no parameters and no output schema, the description covers what it returns, why it's useful, and when to call it. It is fully sufficient for an agent to decide to invoke it confidently.

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?

There are no parameters, so schema coverage is 100% and the baseline is 4. The description correctly avoids repeating the empty schema and adds no parameter-specific semantics, which is appropriate here.

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 clearly identifies the resource (lotteries) and the specific details returned (draw machine size, official ticket lotteries). It distinguishes itself from siblings like latest_results and lottery_results by framing itself as the initial discovery tool with the explicit 'Call this first' instruction.

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?

Provides explicit guidance on when to use: 'Call this first if you are unsure which lotteries are covered or what code to use.' This is a clear trigger, but it does not explicitly spell out when to prefer the sibling tools, though it implies they are for when the user already knows the lottery.

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