espnfantasy_league

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

The annotations already declare readOnlyHint and idempotentHint, so the read-only nature is known. The description adds practical behavior: 'works without a key; ESPN_FANTASY_COOKIE unlocks more if set'. It also clarifies the return shape with a concrete object example, which the schema doesn't provide. No contradiction with 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 description is compact with clear sections: usage guidance, return payload, an example, auth note, and cross-reference. Every sentence earns its place, and the example is highly illustrative.

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 tool's broad 'escape hatch' role and no output schema, the description provides a reasonable return skeleton plus examples. It doesn't enumerate all view effects, but the schema's view enum lists verified values. The cross-reference to sleeper_league is a small extra context. The only gaps are potential error behaviors or rate limits, but the annotation-informed safety profile covers most risk.

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 coverage is 100%, so parameters are individually documented. The description adds a real-world example invocation and explains that scoringPeriodId is required by specific views (mBoxscore, mRoster-at-week, mTransactions2), which the schema description does not fully convey. This helps the agent assemble correct parameter combinations.

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 'Raw league read with ANY combination of views', which is a specific verb (read), resource (league), and scope (any views). It further distinguishes itself as 'the escape hatch when no dedicated tool below fits', clearly separating it from the extensive sibling tools like espnfantasy_teams or espnfantasy_settings.

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 explicitly defines when to use this tool: 'when no dedicated tool below fits, or to fetch several views in one round trip'. This gives both a fallback scenario and a multi-view use case. It implies that when a dedicated tool exists, it should be used instead.

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