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

Annotations already declare readOnlyHint and openWorldHint, so the description's job is to add operational context — and it does: results come 'newest first' and the INJURY type converts the call into a league-wide report rather than a team/player feed. Pagination mechanics are left to the schema, and no contradictions with annotations appear.

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 compact clauses, front-loaded with the verb and result set, with the special-case INJURY behavior called out immediately after. The parenthetical content-type list is long but each item genuinely narrows what the tool returns.

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% parameter documentation, the description only needs to orient the agent, and it does: source, sports, filters, ordering, and the notable INJURY mode. Cursor-pagination behavior is only implied by the schema, which keeps this just under a 5.

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 baseline is 3; the description earns above baseline by adding meaning the schema does not carry, namely that INJURY produces a league-wide injury report and that sport is mandatory for every call. Team/player filter semantics and the position pairing are left entirely to 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?

States a specific verb and resource ('Get FanDuel Research player and team updates') and enumerates the item kinds (injuries, recaps, transactions, lineups, game updates, outlooks). It does not explicitly contrast with nearby siblings such as fanduel_sportsbook_player_news or fanduel_research_articles, but the source and content scope are clear enough to pick it out.

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?

Gives concrete usage context: it needs a sport, works for NFL/NBA/MLB/NHL, and can be filtered by team or player. It also names the special mode ('news_type INJURY makes it a league-wide injury report'). No explicit when-not-to-use or named alternative is given, so it falls short of 5.

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