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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds valuable behavioral context: it notes the payload size (~140 KB at 10 rows) and the default of 3 rows per board, which helps an agent understand performance implications. It also clarifies that 'active' means a bout in the last ~18 months, which is a behavioral definition not in the schema. This exceeds the baseline for annotation-covered tools.

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 two sentences with no waste. The first sentence front-loads the core purpose and the key differentiator (all-time and single-night records an agent quotes). The second sentence efficiently lists the narrowing dimensions. Every phrase earns its place, and the structure is scannable.

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?

For a read-only, idempotent tool with 100% schema coverage and no output schema, the description is nearly complete. It covers what the tool returns (top rows of every leaderboard grouped by category), the key parameters, and a performance note. The only minor gap is that it doesn't explicitly state the return format (e.g., JSON structure), but since there's no output schema and the description says 'the top rows of every leaderboard,' an agent can infer the shape. The performance note about payload size is a strong addition.

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 the schema already documents all 6 parameters thoroughly. The description adds value by explaining the default top=3 and the payload size trade-off, and by clarifying the 'active' population definition. It also groups the scope options into 'one kind of board' and notes the country/active exclusion, which helps an agent understand parameter interactions beyond the schema.

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's purpose: retrieving the Record Book for one promotion in a single call, with the top rows of every leaderboard grouped by category. It distinguishes itself from siblings like get_leaderboard by emphasizing the all-time and single-night records an agent quotes, and the scope options (division, country, active fighters) add specificity.

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 implies when to use this tool: when an agent needs the full record book for a promotion, including all-time and single-night records. It doesn't explicitly name alternatives like get_leaderboard or compare_fighters, but the context signals and sibling list suggest it's the comprehensive record-book endpoint. The description could be stronger with an explicit 'use this instead of get_leaderboard when you need the whole book' statement, but the scope and grouping language provides clear context.

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