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

With no annotations, the description carries the burden of behavioral disclosure. 'List all' implies a read-only, exhaustive operation with no side effects, and the example families give concrete expectations. However, it does not detail the return format or any potential limitations (e.g., pagination), though for a small fixed set this is minor.

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 a single, concise sentence with no unnecessary words or repetition. It front-loads the main action and includes examples for clarity.

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 no-parameter listing tool with no output schema, the description is nearly complete: it names the resource, scope, and examples. It could explicitly mention the return value (e.g., 'returns an array of family names'), but the behavior is still unambiguous. A score of 4 reflects this minor gap.

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 tool has zero parameters, so the baseline is 4 per the rubric. The description adds no parameter-specific details, but none are needed.

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 the tool's purpose: 'List all playable game families supported by the engine' with specific examples (chess, draughts, go, reversi, shogi, xiangqi). This is a specific verb+resource combination that distinguishes it from sibling tools like rules_list_games or play_list_variants.

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 use when you need to know which game families are playable, but it does not explicitly state when to use this versus alternatives. No exclusions or comparisons to other list tools are provided, so guidance is implicit rather than explicit.

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