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

No annotations are present, so the description carries the full disclosure burden. It discloses the monetary cost per reveal, grid dimensions, mining density, and the return payload including the commitment-hash trust property. It does not explicitly state side effects (e.g., whether money is deducted on each call or whether reveals accumulate), but for a no-arg tool the coverage is strong.

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 information-dense sentences with zero filler. Resource and cost are front-loaded first, followed by player context and return values in order of importance. Every sentence earns its place.

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 no-argument, no-output-schema tool, the description covers cost, scale, return payload, and the commitment-hash proof adequately. It could clarify the precise reveal mechanics (whether each call spends a cent), but nothing critical an agent needs to invoke it 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 tool has zero parameters and 100% schema coverage, so there is nothing for the description to add about arguments — the baseline 4 for the no-parameter case applies. The description correctly avoids inventing parameter chatter.

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 resource ('the shared minefield'), its mechanics (100x100 grid, 15% mined, a cent to reveal a square), and the solo-play capability. The phrase 'no opponent needed' distinguishes it from opponent-based siblings like arena_clash, arena_gauntlet, and arena_splitsteal. There is slight ambiguity over whether the call itself performs the charged reveal or merely returns current state, but the core purpose is clear.

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?

'Works with a single player — no opponent needed' gives a clear selection context, implying it should be used when the agent operates alone rather than against an opponent. However, it does not explicitly name alternatives or spell out when-not-to-use rules, leaving sibling differentiation to inference.

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