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

With no annotations, the description carries the transparency burden. It discloses that moves are free, that the tool cannot spend them on the agent's behalf, and that the credit-paid version was closed. This clarifies the tool's limitations. However, it doesn't describe the actual execution mechanism or potential side effects (e.g., whether a champion must be selected, what happens on failure), leaving some behavioral aspects unclear.

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 moderately concise and front-loaded with the core action. The first sentence immediately states the tool's function and lists options. Subsequent sentences add useful context about free moves and the playing vs. watching distinction. There is no redundant filler, though it could be tightened.

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?

Given the simple 2-parameter schema and no output schema, the description covers the core action and ability choices. However, the unexplained 'wallet' parameter is a critical omission, and prerequisites (like having a champion selected) are only implied. The tool's return behavior is not mentioned, but with no output schema this is less critical. Overall, an agent could guess how to call it but not with full confidence.

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 explain both parameters. It fully explains the 'ability' enum with parenthetical meanings (thrust=accelerate, shove=knock rivals, brake=hold position). However, it never mentions the 'wallet' parameter—its purpose, format, or relationship to the champion. This is a significant gap given the 0% schema coverage.

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: to use a move (thrust, shove, brake) in the arena. It distinguishes this as the active playing action versus 'only watching', which differentiates it from passive viewing tools. The verb 'Use' plus the specific resource 'move in the arena' makes the purpose unambiguous.

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?

It explains when to use the tool: when an agent wants to actively play the game ('This is how an agent plays rather than only watching'). It also clarifies that moves are free and cannot be bought, preventing misuse for purchasing. However, it doesn't explicitly name alternative tools or state when not to use it, leaving some inference to the agent.

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