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

Goes well beyond the readOnlyHint/openWorldHint annotations by disclosing the data provenance (the JSON FanDuel's own web app loads), coverage limits (no props or futures, only currently listed games), and a non-obvious commercial trait: $0.002 USDC per successful call via x402 on Base/Solana/Arc, with failed calls not charged. Missing only freshness/latency expectations for the scraped feed.

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 and league/field coverage come first, with exclusions and pricing trailing — good front-loading. It is a single very dense run-on sentence, and the odds-format enumeration is slightly over-packed, but no sentence is wasted.

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-shape detail is optional and the description refrains from over-explaining it beyond a quick field summary. Payment model, coverage limits and data source are all covered; only freshness/pagination expectations are unstated for a paid, open-world read tool.

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 100%, so team, limit and league are already documented at the field level. The description adds the set of supported leagues in prose (including college football/basketball, which maps to ncaaf/ncaab) and clarifies that filtering is against currently listed games, but nothing about limit/pagination behavior. Baseline 3 applies when the schema carries the parameter burden.

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 verb and resource (FanDuel game lines for NFL/NBA/MLB/NHL/WNBA/college) and enumerates exactly what each row contains (event ID, teams, start time, moneyline, spread/puck line, total, American and decimal odds). The book-specific + New Jersey scope naturally distinguishes it from siblings like dev_pinnacle_odds or dev_espn_nba_scoreboard, though no sibling is named explicitly.

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?

Scope exclusions are stated ('only games FanDuel currently lists, no props or futures'), which usefully rules out prop/futures queries. However there is no explicit 'use this instead of X' routing against the many other odds/scoreboard siblings, so the agent must infer that this is the FanDuel-priced-lines option versus ESPN scoreboards or Pinnacle odds.

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