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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description's only behavioral contribution is 'several result sets', which hints at multi-table output but is not elaborated, and the rest of the sentence is a verbatim duplicate rather than added context.

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 single sentence is repeated twice word-for-word, including the awkward doubled 'splits splits', so roughly half the text is pure waste. Nothing is front-loaded beyond the weak verb 'Get Returns'.

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?

An output schema exists and all six parameters are documented in the schema, so the raw requirements are covered elsewhere. Still, for a six-parameter split-reporting tool the description gives no indication of what the several result sets contain or how splitting works, leaving the agent to infer the tool's purpose entirely from its name.

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% and each parameter carries its own explanation (season format, per_mode default, league_id constraint, player_id source), so the schema does the work. The description adds no parameter meaning beyond that, which is the baseline 3 for fully documented schemas.

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 restates the tool name almost verbatim ('Returns one player's by game splits splits as several result sets'), leaving 'by game splits' undefined. It does convey that results are scoped to a single player and delivered as multiple result sets, but it never distinguishes this tool from nba_team_dash_by_game_splits or nba_player_dash_by_clutch in the sibling list.

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?

There is no when-to-use guidance, no mention of prerequisites (player_id plus season), and no routing to any alternative such as the team-level or clutch split variants. The only hint is implicit in the tool name itself.

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