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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuine behavioral detail beyond that: Sportsbook prices and selection ids are only populated "for games not yet finished," which tells the agent why odds may be absent for completed games. It doesn't address rate limits, caching, or freshness beyond that caveat.

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 payload enumeration and the usage constraint are front-loaded, and there is no filler. The single long field-list sentence is dense but each item is informative, and the closing sentence covers the input requirement without repetition.

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 an output schema present and 100% schema description coverage, the description needn't restate return structures, yet it still summarizes contents and flags the unfinished-games caveat for odds. What remains unaddressed is pagination/boundedness and any freshness or auth considerations, minor for a single-week schedule read.

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%, with week ranges spelled out per season_type in the schema itself, so the baseline of 3 applies. The description only paraphrases the same season_type values (PRE, REGULAR, POST) and adds no syntax or edge-case detail beyond what the schema already states.

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 opens with a specific verb+resource+scope ("Get one week of the NFL schedule from FanDuel Research") and enumerates the returned fields, so an agent knows exactly what payload to expect. The source qualifier (FanDuel Research vs. Sportsbook) gives partial sibling differentiation, but the near-identical sibling fanduel_research_fixtures and fanduel_sportsbook_schedule are never named or contrasted.

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?

"Use it for game-day context" gives a clear situational trigger, and the trailing clause spells out the required inputs (a week plus season_type PRE/REGULAR/POST). There is no explicit when-not guidance or named alternative tool for the fixtures/sportsbook-schedule variants.

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