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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description carries a lower burden. It adds valuable behavioral context by stating that every item has an equal chance and that the chosen item is returned, clarifying that results vary across calls despite the read-only and idempotent annotations.

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 description is short, front-loaded with the core action, and adds only the essential behavioral guarantee and return value. The source URL is minor but does not bloat the definition.

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-parameter tool with a well-defined input schema, output schema, and annotations, the description covers purpose, randomness, equal chance, and return behavior. Nothing necessary for correct invocation is missing.

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?

The single items parameter is fully documented in the schema with type, min/max constraints, and a description, so schema coverage is 100%. The description only rephrases items as 'names or options' and does not add meaningful per-parameter detail, so the baseline of 3 is appropriate.

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 states a specific verb and resource: spinning a wheel of names or options and randomly selecting one. It also specifies the uniform probability and return value, which helps differentiate it from sibling randomizers like coin_flip, dice_roller, or random_number_generator.

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 description implies usage for uniformly random selection from a user-supplied list, but it does not explicitly say when to prefer this tool over siblings such as yes_no_wheel, spin_the_bottle, or random_team_generator. No alternatives or exclusions are mentioned, so guidance remains only implied.

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