yahoo_player_ownership

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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the description does not need to restate those. It adds valuable transparency by warning that the return shape is unverified, that the provider key is not held, and that the payload should be inspected before relying on field names. It also discloses auth requirements.

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 longer than average but well-structured with clear sections: summary, return shape, caveat, example, and auth. Every section earns its place, especially the unverified-shape warning and example. The dense return-shape block is necessary because there is no output schema.

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 absence of an output schema, the description compensates by providing the vendor-documented return shape, a caveat about its reliability, a usage example, and auth instructions. It is complete enough for a simple read-only lookup, though it does not cover error cases or pagination.

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%, with each parameter already described in the input schema. The description adds a concrete example with realistic leagueKey and playerKeys values, but it does not add substantive semantic meaning beyond what the schema already provides. Baseline 3 is appropriate.

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 identifies the tool's resource: ownership and roster status for league players, including percent owned and whether they are rostered, on waivers, or free. It is specific enough to distinguish from sibling tools like yahoo_player_stats or yahoo_team_roster, though it does not explicitly name or contrast those alternatives.

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 example 'Is this player available?' implies the primary use case, and the explanation of ownership_type ('add them now' vs 'you must outbid someone') provides practical context. However, there is no explicit when-to-use versus alternatives or any exclusion guidance.

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