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

With no annotations, the description carries the full disclosure burden. It usefully states the return shape (individual results plus total) and the count range 1–20, and hints at fairness/trustworthiness, but says nothing about determinism, seeding, or repeatability that the 'trust' phrasing gestures at.

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?

Three short sentences, front-loaded with the verb and inputs, then the return shape, then the use case. No filler and nothing redundant.

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 stateless tool with no output schema, the description covers the action, the two main inputs, and the return value. It still leaves the locale parameter and its purpose unexplained, a real gap given 0% schema description coverage.

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 0%, so the description must compensate. It documents count (1–20) and sides with examples, but completely omits the third parameter locale (enum en/zh), leaving one of three parameters undocumented anywhere.

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 ('Roll dice') and the two core inputs, so the agent knows exactly what the tool produces. It does not differentiate itself from the conceptually adjacent sibling random-picker, but the core purpose is unambiguous.

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 final sentence gives an implied use case ('tabletop games or random rolls the user should be able to trust'), which hints when to reach for it. There is no explicit when-not guidance or named alternative (e.g. random-picker), so usage is only implied.

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