yahoo_league_transactions

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

The annotations indicate readOnly, openWorld, and idempotent, and the description does not contradict them. It adds a caveat that the return shape is from vendor docs and may be unverified, which is helpful transparency. However, it does not elaborate on other behavioral aspects like error handling or data freshness beyond that, so it provides only moderate added value beyond the 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 well-structured with clear sections for the summary, return shape, example, and auth note. It contains necessary details without being excessively verbose. The inclusion of the return shape and example is useful, though the return shape description is somewhat lengthy and could be trimmed, but overall it is concise enough for its purpose.

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?

The description provides the core functionality, expected output shape, an example request, and authentication requirements. It also includes a caution about the unverified vendor documentation. Given the tool's simplicity (two parameters) and that annotations cover read-only/idempotent nature, the description is fairly complete. It lacks details on error scenarios, but that is minor given the clarity of the rest.

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 provides descriptions for both parameters (format and leagueKey), and the tool description does not add further meaning beyond what is already in the schema. The parameters are straightforward, and the description's mention of leagueKey in the example reinforces its role, but it does not provide additional semantic depth that the schema lacks. Since schema coverage is 100%, the baseline score of 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?

The description clearly states the tool's function: 'Adds, drops, waiver claims and trades across the league — who is doing what.' This unambiguously indicates it retrieves league transaction data, and it is distinguishable from other Yahoo tools which focus on different aspects (e.g., standings, teams, players). It could be more explicit by using 'Get' or 'Fetch', but the meaning is clear.

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 does not explicitly state when to use this tool over alternatives, but it is implicitly clear that it is for transactions. There are no obvious sibling tools for transactions, so the usage context is implied by the name and description. However, it lacks explicit guidance on use cases or when not to use it, so it falls short of a higher score.

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