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 that the output is a 'complete' set of selector values (an enumeration, not a filtered list) and how they feed fotmob_league, but does not elaborate on structure, ordering, or rate behavior. Modest added value over 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?

One sentence, front-loaded with the resource and its scope, with the sibling references tacked on at the end. Zero filler.

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?

An output schema exists so return values need not be described, and annotations cover the safety profile. The description supplies the input provenance and the downstream call, making it nearly complete for a one-parameter lookup tool; only the nature of the returned values is left slightly vague.

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% and the single parameter's description already states it is a 'Required numeric FotMob league id from fotmob/leagues.' The description merely reinforces the same origin, adding no format or validation detail beyond the schema. Baseline 3 applies.

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 resource ('FotMob league season selector values') scoped to a league id, and names both the upstream source (fotmob_leagues) and the downstream consumer (fotmob_league). This lets an agent distinguish it from those siblings, though the phrase 'season selector values' is slightly jargon-y about what is actually returned.

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?

Gives clear workflow context: get the league id from fotmob_leagues, then use the returned season values with fotmob_league. This implicitly tells the agent when to reach for this tool, but there is no explicit 'when not to use' or alternative-selection rule.

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