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

Annotations already declare readOnlyHint and openWorldHint, so the bar is lower. The description still adds useful context: that suggestions come from the site's own search box, that matched text is highlighted in the output, and what entity types can surface.

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, front-loaded with the operation and followed by the practical use case. Slight redundancy in repeating the 2-character minimum already present in the schema, but no wasted prose.

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?

Two params, an output schema, and full annotation coverage mean little else is needed. The description makes clear this is a typeahead endpoint returning highlighted suggestions, which is enough to call it correctly.

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 q and limit are already documented with ranges and defaults. The description only restates the 'at least 2 characters' rule and adds the entity categories covered, which is marginal 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?

States a specific verb ('Get ... suggestions') and resource ('the FanDuel Sportsbook search box'), and scopes it to a typed prefix over players, teams and competitions. It implicitly separates itself from the sibling fanduel_sportsbook_search by framing this as completion rather than search, but never names the alternative explicitly.

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 to turn a partial name into a search term' gives clear implied usage as a pre-search step. No explicit when-not or routing to fanduel_sportsbook_search when a full query is already known, so guidance is implied rather than stated.

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