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

With no annotations, the description carries the full burden. It usefully discloses the return contents (win status, prize category, amount, redemption period), which is valuable given no output schema. It says nothing about permissions, rate limits, or whether the period defaults matter behaviorally.

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 front-loaded sentence that gives the purpose, the required input, and the return payload with zero wasted words. Nothing extraneous.

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 simple read-only lookup with full schema coverage, the description covers purpose, input, and return values. It is nearly complete, lacking only sibling differentiation and the period-default behavior, which are minor for this tool's complexity.

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%, so both parameters are already documented in the schema. The description reiterates the 8-digit format of 'number' but says nothing about the 'period' parameter or its 'latest period' default, adding little beyond the schema.

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 and resource (對統一發票 / check uniform invoice) plus the concrete result set (win status, prize category, amount, redemption period), so an agent knows exactly what it does. However, it never names or differentiates from the sibling check_lottery or get_invoice_numbers, leaving potential ambiguity.

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?

Implies usage by saying 'input an 8-digit invoice number,' which sets the precondition for invocation. There is no explicit when/when-not guidance and no reference to alternative tools like check_lottery, so usage context is only inferred.

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