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

Annotations already declare readOnlyHint=true and idempotentHint=true, covering the safety profile. The description adds valuable behavioral context: results are included only 'when the card has been fought,' estimated start times are 'estimates, not a schedule' and 're-anchored on each completed bout,' and odds are 'information only, not betting advice.' These caveats go beyond the annotations and help the agent set expectations.

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?

Two sentences with no filler. The primary purpose and return details are front-loaded, and the include options are explained efficiently. Every word contributes value.

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 adequately enumerates all expected response components and the conditional inclusion of results. The conditional behavior and the include parameter effects are covered. For a single-event read tool with safe annotations, nothing an agent needs to invoke it correctly is missing.

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 both parameters are documented in the schema. The description adds extra nuance by explaining what the include values do in plain language and clarifying the default return payload ('complete bout order, both corners, venue, broadcast listings and results'). This enriches understanding beyond the schema's bare descriptions, justifying a score above the baseline 3.

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 verb 'Fetch' and the resource 'one event by slug or id' and enumerates the full card contents: 'complete bout order, both corners, venue, broadcast listings and results.' This distinguishes it from sibling tools like get_fight, get_event_odds, and get_event_live, which target narrower aspects.

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 the tool (to get a comprehensive event card) and explains the include parameter options, but it does not explicitly name alternatives or provide when-not-to-use conditions. The context is clear enough, but no exclusions are stated, so it falls short of a 5.

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