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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds that access is public, that no match_id is required, and gives a literal empty-argument invocation example — real value beyond the structured fields, though it says nothing about result shape or ranking parameters.

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 short clauses, front-loaded with the tool name and the WHEN condition, ending with a concrete call example. Nothing is padding.

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?

Annotations, a full schema, and an output schema are all present, so the description only needs to route and scope. It does both and adds an example; the only modest gap is not hinting at what the boards contain or whether results are paginated.

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% and the single optional 'key' parameter is fully documented there, including the Authorization: Bearer alternative. The description adds only the negative constraint that no match_id is needed; it never mentions 'key'. Baseline 3 is appropriate.

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 states a specific verb and resource ('read Rogue Colosseum attacker/hardened leaderboards') and explicitly names the two sibling tools it is not, so an agent can place it in the fleet without opening any schema.

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?

It gives an explicit WHEN clause and then draws the boundary against stats_leaderboard and arena_leaderboard ('public Arena games, not Colosseum'), which is exactly the discrimination an agent needs. No exclusions remain implicit.

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