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

Annotations already establish readOnlyHint=true, destructiveHint=false, so the safety profile is covered. The description adds genuinely useful non-schema behavior: the 5-credit cost and the historical coverage boundary (seasons from 2010-11 on), both of which affect whether an agent should call it.

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?

Four tight sentences, front-loaded with the trigger condition, then output contents, then the two operational constraints (season range, cost). No sentence is redundant with another, and nothing is buried.

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?

With an output schema present, the description needn't enumerate return fields, yet it usefully previews the stat categories available. Combined with the cost and season-range notes, an agent has everything needed to decide and call correctly; only the fallback routing to a sibling for non-leaderboard queries is unstated.

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%, so every parameter (team, league, season, sort_by, min_games, limit) is already documented with defaults and formats. The description echoes the sort metrics and the games-played filter without adding syntax or semantics beyond the schema, so baseline 3 applies.

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?

States a concrete verb+resource pair: returns a ranked skater leaderboard with sortable metrics and filters. It implicitly differentiates from get_player_stats (single-player) and get_goalie_stats by framing itself as a leaderboard, but never names those siblings, so differentiation is inferred rather than explicit.

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?

"Use when ranking skaters or comparing scoring" gives a clear selection context, which is exactly the scenario where a leaderboard tool beats a per-player tool like get_player_stats. It stops short of explicit exclusions or naming the alternative tool, so it clears the bar for clear context but not full when/when-not guidance.

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