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

Beyond the annotations (read-only, idempotent, non-destructive), the description adds substantial behavioral detail: it is network-only with no offline fallback, returns a clean ALL_SOURCES_FAILED envelope when no key is configured, and describes the exact return shape plus the meta.source adapter. This gives an agent full transparency about failure modes and response structure.

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 description is compact and well-structured with clear sections for purpose, network requirements, args, and returns. Every line earns its place, and the primary purpose is front-loaded. No redundant or filler content.

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 single-parameter tool, this description is complete. It explains the data requirement, the failure envelope, the return fields, and the source adapter. Even though an output schema exists, the description's return breakdown adds practical clarity, and nothing an agent needs to call it correctly is missing.

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 input schema already covers the single parameter 'team' with a clear description ('API-Football numeric team id (not a country code)') and 100% coverage. The description repeats this information in the Args section without adding any new semantic meaning, so it meets 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 opens with a specific verb ('Return') and an unambiguous resource ('a team's aggregate World Cup tournament statistics'), which clearly distinguishes it from sibling tools that return fixtures, standings, or individual match data. Even though the tool name says 'match_stats', the description clarifies it is aggregate tournament statistics, so an agent knows exactly what it gets.

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 description implies when to use the tool: whenever a team's aggregate World Cup statistics are needed. However, it does not explicitly state when not to use it or name alternatives among the many football sibling tools. It does add a practical usage constraint (requires an API key and only works in network-enabled contexts), which supports usage decisions.

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