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

Goes well beyond the readOnlyHint/openWorldHint annotations by disclosing cost ($0.002 USDC per successful call), the payment rails (x402 on Base, Solana or Arc), and that failed calls are not billed — material for an agent deciding whether to invoke. It also states the data provenance (the NRL site's own ladder data), which is not visible anywhere in the structured fields.

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?

Two sentences, front-loaded with what the tool returns, followed by scope and cost. The field enumeration is long but each item is a concrete returned value rather than filler; only minor trimming would be possible.

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?

With an output schema present, return-value shape need not be re-explained, and annotations plus the cost paragraph cover safety and billing. The only remaining gap is data freshness (whether the ladder is a live snapshot or end-of-season), which an agent might reasonably want.

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 single parameter has 100% schema coverage, including the 2000–2026 range and the 2026 default, so the schema already carries the semantics. The description adds nothing about the season argument (e.g. behavior for out-of-range or future seasons), which is the baseline 3 case.

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?

Names the exact resource (NRL Telstra Premiership ladder for a given season) and enumerates the returned fields — position, club, played, wins, draws, losses, for/against, differential, points, form, streak. The explicit scope line 'Season stats only; no player stats' separates it from player-level sports siblings without needing a schema inspection.

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 exclusion 'Season stats only; no player stats' gives a clear when-not signal, and the pricing/trial framing helps the agent decide whether to spend. It stops short of pointing to a named alternative sibling (e.g. a player-stats tool) for the excluded case.

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