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

Annotations already cover the safe-read profile (readOnlyHint, destructiveHint=false, openWorldHint). The description adds operational context beyond them: parallel-safe, upstream cost 2-3, and the actual return shape (main-event-first order, weight class, title stakes, per-league fighter details, result fields). Return structure is largely covered by the output schema, so this stops short of a 5.

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-loads the core purpose, then uses scannable labeled blocks (When to use, Prefer over, Do not use when, Parallel-safe, cost, example). Every line carries distinct information; 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?

For a composite read tool with an output schema and full schema coverage, the description supplies selection guidance, cost/parallelism hints, and result-shape notes. An agent has everything needed to call it correctly and route around it when appropriate.

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 parameters are fully documented in the schema (event slug / next / last, limit 1-40, league enum with league meanings). The description restates the slug-or-'next'/'last' convention and adds one extra example slug, but does not meaningfully extend beyond the schema, so the 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 specific composite verb+resource: a full fight card (event identity + ordered bouts with results) for one RAF or BKFC event. It explicitly names what it is not (combat_events, combat_bout), so an agent can distinguish it from siblings without opening schemas.

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?

Provides explicit 'When to use' example queries, a 'Prefer over: combat_events + call_api per bout' rule, and a 'Do not use when' exclusion pointing to combat_bout. Nothing about selection is left to inference.

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