yahoo_league

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

Annotations already indicate read-only, idempotent behavior, and the description adds valuable caveats: the return shape is from vendor docs and unverified, auth requires a key in specific environment variables, and the note to inspect actual payloads. This is beyond what annotations provide and is critical for an agent to avoid relying on unverified field names.

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 well-structured and front-loaded with purpose, then provides return shape, a critical caveat, an example, and auth requirements. Each sentence serves a distinct purpose without redundancy. The formatting uses line breaks for readability, making it easy to scan.

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 the lack of an output schema, the description fully details the expected return shape, including specific field names and type hints. It also covers verification status, auth prerequisites, and a usage example. It is complete enough for an agent to invoke the tool correctly and interpret results.

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 schema already describes both parameters (format and leagueKey) with 100% coverage, so the baseline is 3. The description adds a concrete example ('449.l.12345'), explains that leagueKey comes from yahoo_my_leagues, and implies its role as part of the URL path, adding meaning beyond 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?

The description clearly states the tool's purpose: 'League metadata: name, size, scoring type, current week, and the season's week range.' This is specific and distinguishes it from sibling tools like yahoo_league_settings or yahoo_league_standings, which focus on other aspects. The mention that 'current_week drives every week-scoped call below' further clarifies its role as a foundational metadata lookup.

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 usage context by stating that 'current_week drives every week-scoped call below,' which signals that this tool should be used first to obtain the current week. It also provides an example and notes the leagueKey comes from yahoo_my_leagues, giving workflow context. However, it does not explicitly name alternative tools or state when not to use it, so it falls short of a 5.

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