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

Beyond readOnlyHint/openWorldHint, it discloses the upstream source (ESPN public API), the 16-league coverage ceiling, the x402 payment requirement ($0.002 USDC per successful call on Base, Solana or Arc) and that failed calls are not charged. The pricing and payment-rail detail is exactly the kind of operational context annotations cannot convey.

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 capability statement is front-loaded and dense, but two sentences are spent advertising unrelated tools (TeamRankings NBA/NFL, Bundlephobia) that will rarely be confused with soccer tables. The pricing clause is long but earned; the sibling-routing clause is mostly filler that dilutes the useful routing information.

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 an output schema exists, return values need not be described, and the definition still covers coverage scope, source, views, season semantics and cost. It does not state failure behaviors (unknown league slug, out-of-range limit) or whether seasons before the current one are complete, which leaves small gaps for a paid, open-world 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 the baseline is 3; the description goes further by enumerating the per-view payloads (table columns vs. the scorers/assists fields with appearances, goals, assists and club) and by noting season applies to tables only, which sharpens the view/season interaction. The league and limit parameters are left entirely to the schema.

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 concrete verb+resource: league table (rank, team, played, W/D/L, goals, GD, points, qualification note; any season) or current-season top scorers/top assists, across 16 named leagues. It also resolves the naming confusion by saying the data comes from ESPN's public API because FBref blocks automated access. An agent knows exactly what this returns without opening the schema.

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 does route the agent away to alternatives (dev_teamrankings for NBA/NFL team stat tables, dev_bundlephobia for npm bundle size), but those are cross-domain tools, not the genuinely confusable soccer siblings such as dev_espn_standings, dev_flashscore, dev_sofascore_live, dev_pro_football_reference or dev_understat_xg. There is no explicit when-not guidance for overlapping soccer stats sources, so selection between similar tools is left to inference.

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