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

With no annotations, the description carries the full burden and does disclose genuinely useful facts: moves are free, cannot be purchased at any price, and the tool will not consume a move on your behalf. That is real behavioral context rarely found elsewhere. What it never states is what a call actually returns or its side effects, and the 'credit-paid version closed 18 September 2026' note is historical trivia rather than operational guidance.

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 core statement is front-loaded, which is good, but the passage wanders into self-referential asides ('and says so'), a dated pricing-history parenthetical, and a closing motivational sentence. Several clauses do not help an agent decide or invoke.

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 two-required-parameter tool with no annotations, no output schema, and zero schema description coverage, the description leaves the wallet parameter and the return behavior entirely unexplained. The free-vs-paid discussion is thorough, but the invocation-critical details an agent needs are absent.

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 coverage is 0%, so the description must compensate. It does explain the 'ability' enum well by glossing thrust as accelerate, shove as knocking rivals, and brake as holding position — meaning the bare enum lacks. The required 'wallet' parameter is never mentioned at all, leaving half the inputs undocumented.

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 first sentence names a verb and resource and glosses all three move options, so the domain is clear. But the follow-up 'this tool cannot spend one for you, and says so' directly undercuts what invoking it actually accomplishes, leaving the agent unsure whether it acts or merely informs. Siblings graviton_state and graviton_how_to_play are only indirectly gestured at ('plays rather than only watching').

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 gives sequencing context: 'pick a champion, then push it with moves while the round runs', which implies a prerequisite step and timing. However, no sibling is named, and there is no explicit when-not guidance (e.g. use graviton_how_to_play for rules, graviton_state for standings), so the agent must infer routing.

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