Lines across books

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and external-data behavior are covered. The description usefully adds the authentication requirement (DRAFTKINGS_API_KEY, where to obtain it), which the annotations do not convey, but says nothing about pagination, rate limits, or what the response looks like for a comparison endpoint.

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 short sentences with the capability stated first and the auth requirement second; no filler. The sign-up URL is slightly promotional but does earn its place by telling the agent how to resolve the missing-key case.

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 an 8-parameter, zero-required comparison tool with no output schema and sparse schema descriptions, the definition is thin: it does not explain what a returned line comparison contains, how the many optional filters interact, or what an empty/limited result means. The API-key note is helpful but does not compensate for the missing parameter and result context.

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 only 25%, so six of eight parameters (stat, team, league, player, with_fair, market_type) carry no documentation. The description only illuminates with_fair via "optional fair price"; it gives no meaning for the filtering parameters or the market_type enum, leaving the schema gap largely unfilled.

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?

"Lines across books with an optional fair price" identifies the resource (sportsbook lines compared across books) and hints at the with_fair option, but omits an explicit verb and never distinguishes itself from close siblings such as get_compare, get_arbitrage, or get_odds. An agent can guess the domain but not precisely what this returns versus those alternatives.

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?

There is no when-to-use guidance, no prerequisites beyond the API key, and no mention of alternatives. The agent must infer that this is the cross-book comparison tool rather than get_compare or get_odds from the name alone.

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