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

With no annotations, the description carries the behavioral disclosure burden. It transparently states that gameplay involves no stake, deposit, or prize, ruling out financial side effects. The 'how to play' framing makes it clear this is an instructional tool, though it does not explicitly state the return format.

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, front-loaded sentence that covers purpose, mechanics, and exclusions without filler. Every clause adds useful information.

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 zero-parameter instructional tool with no output schema, the description is complete enough: it explains what the Arena is, how to play, and the key caveat that it is free with no stakes.

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 of 4 applies; there are no inputs for the description to clarify.

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 identifies the resource ('Graviton Arena'), the activity ('play'), and the core mechanics: pick a champion, spend free boosts, keep it alive. It also distinguishes itself from betting-related siblings by explicitly stating 'No stake, no deposit, no prize.'

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 gives clear context that this is for the free-play Arena rather than for staked or betting activity. It does not explicitly name an alternative tool like graviton_how_to_bet, but the 'free' and 'no stake' language effectively signals when this tool applies.

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