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 covered. The description adds behavioral context by specifying the structure of the data (1v1, 1v2, ..., attempted vs won) and the global leaderboard option, which goes beyond the annotations and clarifies response semantics without contradiction.

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, front-loaded sentence that states the purpose first, then explains the two modes. It contains zero fluff and every clause carries essential information, making it optimally 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?

Given the tool is a simple read-only stats query with full schema coverage on both parameters and an output schema provided, the description fully covers the invocation variants (player vs global). No additional context is needed for correct usage; the output schema handles return format details.

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 description coverage is 100% for both parameters, so the baseline is 3. The description adds value by explaining that playerId triggers a specific breakdown (listing clutch scenarios) and that omission yields the global leaderboard, which is more semantic detail than the schema's 'if omitted, returns global leaderboard' explanation.

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 provides '1vX clutch situation success records' and distinguishes between two modes: per-player breakdown or global leaderboard. This uniquely identifies the tool's resource and differentiates it from sibling tools like cs2_opening_duels or leaderboard_aces.

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 gives clear usage context: pass playerId for a player's breakdown, omit for global leaderboard. While it doesn't explicitly name alternatives or exclusion criteria, the conditional usage is unambiguous and effectively guides the agent on how to invoke the tool for the desired result.

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