Leaderboards and totals

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description goes further with real behavioral caveats: ties share a place, experience and tamed counts are lower bounds because vanilla keeps no lifetime total, and the max of 5 boards. It stops short of saying how expensive the scan is or how ties are ordered within a place.

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?

Front-loaded with the core behavior, and nearly every clause carries new information (units, presets, syntax, defaults). The final sentence is a dense run-on listing aggregate fields, which costs it a point on readability, but there is no filler.

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 no output schema, the description must imply the return shape; it does so partially by describing ranked entries with shared places and a totals mode with named aggregate fields. It never states the overall structure (e.g. how multiple boards are keyed in the response), which is the remaining gap for a 2-param aggregation tool.

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 coverage is 100% so the baseline is 3, but the description substantially exceeds it: it enumerates every preset with its unit (playtime in hours, travel in km, damage in hearts, netherite as ancient debris) and defines the free-form `category:key` syntax with examples like `custom:jump` and `killed:*`, plus wildcard support. That is meaning the schema's one-line example does not convey.

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?

Opens with a specific verb+resource+scope: 'Players ranked by statistics, up to 5 boards at once.' It is instantly distinguishable from the player-inspection siblings (get_player, list_players) because it declares ranking/aggregation as its output.

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 second half establishes an explicit branch: pass `statistics` for boards, or omit it to get presets-with-units plus server-wide totals. That is clear usage context, but it never names an alternative tool or states when a sibling would be preferred over this one.

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