list_leagues

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

With no annotations provided, the description carries the full burden. It discloses plan-based access restrictions and explains that the is_specialized flag indicates leagues the engine biases toward, adding meaningful behavioral context beyond the schema. It does not explicitly state read-only behavior, but 'List' strongly implies it, and the additional context is sufficient.

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 concise, front-loaded with the main action, and every sentence provides value—from the plan filter to the output fields to example queries. No redundancy or 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?

Given no output schema and no annotations, the description thoroughly covers what the tool returns (id, name, country, continent, is_specialized flag), notes plan-based restrictions, and even mentions the integration point with list_picks. It is fully sufficient for an agent to understand and invoke the tool correctly.

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 has 100% coverage with clear parameter descriptions, so the baseline is 3. The description adds extra meaning by explaining the is_specialized flag and how the id relates to list_picks, enriching the semantics of the specialized_only parameter and the output's utility.

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 lists soccer leagues tracked by the Statos engine and explicitly mentions plan-based filtering. It differentiates itself from siblings by noting that league IDs can be used with list_picks, making the tool's role in the ecosystem 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 provides concrete use-case examples ('which European leagues can I see?') and explains how to filter for specialized leagues. It does not explicitly contrast with alternative tools, but the discovery-oriented framing and reference to list_picks give clear guidance on when this tool is appropriate.

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