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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is known. The description adds that it returns the 'full roster' with specific fields, which gives some behavioral context (no filtering). However, it does not disclose details like ordering, pagination, or permission requirements, so it remains at the baseline for annotation-covered tools.

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 a single, efficient sentence that front-loads the core action ('Full roster') and packs essential output details. Every word earns its place, making it concise and well-structured.

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, read-only tool with one required parameter, an output schema, and annotations, the description is complete. It states what the tool returns (full roster with specific fields) and the purpose is clear. No additional context is needed for correct invocation.

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 schema provides 100% coverage for the single parameter tournament_key, including its format (starts with tk_). The description adds no additional parameter information, so the baseline of 3 applies as the schema already handles the semantics.

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 specifies the verb 'list' and the resource 'players' (roster), and adds the scope ('full') and key fields (status, level, doubles partner). This distinguishes it from sibling tools like add_players or list_matches, making the purpose unambiguous.

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 clear context that this tool returns the full player roster, which implies its use for overview queries. It does not explicitly name alternatives or exclusions, but the purpose is evident enough for an agent to select it for listing players without confusion.

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