list_sports

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

With no annotations, the description carries the full burden. It discloses what the tool returns (sport_key for all sports) and explicitly notes that 'horse-racing' is absent, directing to racing_* tools. However, it does not detail the exact return structure (e.g., array format), which is a minor gap for a no-arg list tool.

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?

Three concise sentences: purpose, usage, and a critical caveat. Every sentence adds value, and the purpose is front-loaded. No redundant or filler content.

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?

For a simple no-parameter list tool, the description is complete: it states what is returned, when to use it, and a notable exclusion (horse-racing). It also references sibling tools, providing enough context for an agent to select and invoke it effectively.

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 tool has 0 parameters, so the parameter semantics baseline is 4. The description adds no parameter-specific information, but none is needed since the schema is empty and the description focuses on the tool's purpose and output.

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: "Every sport and competition this API currently covers, with its sport_key." It uses the verb 'list' implicitly and identifies the exact resource (sports/competitions) and output field (sport_key), making it distinct from sibling tools.

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?

Explicit guidance is provided: "Call this FIRST if you are unsure of the right sport_key" and "checking here is cheaper" than relying on a 404 from other tools. It also clarifies the alternative for racing (separate racing_* tools), giving clear when-to-use and when-not-to-use context.

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