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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower, and the description usefully confirms the read-only nature and adds the play-happens-elsewhere boundary plus the rules URL. With no output schema, the statement of what is returned (schedule, what's on now, per-game rules) carries meaningful behavioral weight.

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 purpose line is buried after several paragraphs of game lore, and the read-only statement is essentially repeated twice ('playing happens outside it' / 'reads the Arena's schedule and rules; playing happens outside it'). The domain detail is topical but front-loading lore over the purpose costs efficiency.

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, read-only info tool with no output schema, the description adequately covers what comes back (schedule, current events, rules) and where the full rules live. Nothing an agent needs in order to invoke it correctly is 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?

The tool takes zero parameters, which is the baseline-4 case; there are no argument semantics for the description to clarify. Nothing about parameters is misleading or missing.

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 contains a specific verb+resource statement: 'This returns the schedule, what's on now and the rules of each game,' and the read-only scope is reinforced by 'reads the Arena's schedule and rules.' It is clearly about the Arena, separating it topically from anthill_info/anthill_about, but it never explicitly contrasts itself with those siblings.

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 draws one useful boundary — 'playing happens outside it' — so the agent knows this tool does not submit moves. However, it names no alternative tool and gives no explicit condition for choosing this over anthill_info or anthill_about; usage is only implied by the Arena topic.

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