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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: the data source, 20-league scope, and the x402 pricing model with explicit note that failed calls are not charged. It does not cover update cadence or latency, but it goes well beyond the annotations.

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 definition is front-loaded with purpose and data coverage, and every clause conveys relevant information (fields, leagues, filter, pricing). It is dense but not padded; the pricing sentence at the end could be split out, but nothing is superfluous.

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 and full schema parameter coverage, the description does not need to explain return values. It supplies the source, field list, league scope, filtering behavior and payment terms. The only minor omission is update cadence or freshness of the CSV data.

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 all four parameters are already documented, including league codes, season start year, team spelling and limit bounds. The description adds only marginal value by naming example leagues and confirming the team filter, which is roughly the baseline for high schema coverage.

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 names a specific resource and verb: European football match results (historical CSV data) with statistics and betting odds for a league and season. It distinguishes itself through the source, field coverage and odds, but never explicitly distinguishes itself from sibling football tools like dev_espn_soccer_scoreboard, dev_fbref or dev_flashscore.

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?

Usage is implied by 'for a league and season' and 'Filter by team', which suggests historical, season-scoped lookups. However, there is no explicit guidance on when to choose this over the many sibling football/soccer tools, nor any stated exclusions or alternatives.

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