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 usefully discloses crypto-randomness (implying fairness/uniformity) and that one item is returned, but says nothing about behavior on an empty list, duplicate handling, or how the locale parameter affects output.

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 with the core action front-loaded and no filler. Slightly clipped style ('Input: `items` (array). Returns the chosen item.') is efficient rather than noisy.

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 one-required-param tool with no output schema, the description covers input, output, and purpose adequately. The unexplained `locale` parameter and absent edge-case behavior keep it from being fully complete.

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 only `items` (array) and skips the `locale` enum parameter entirely, leaving a required-looking dimension of behavior unexplained in both schema and prose.

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: 'Pick one item at random from a list', and adds the mechanism ('crypto-randomness'). Clear enough to distinguish from randomness-adjacent siblings like dice-roller, but it does not name or contrast with any sibling explicitly.

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?

'Use for fair raffles or decisions' implies a usage context but gives no when-not conditions, prerequisites, or alternatives. An agent can infer the domain but gets no routing guidance relative to dice-roller or quiz.

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