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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), but the description adds real value beyond them: a concrete cost model (10 credits for up to 200 games) and a firm compliance constraint forbidding stake/payout calculations, bet recommendations, or sportsbook referrals. It also discloses what a returned row contains, which is unusually concrete for a read tool.

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?

Front-loaded with the purpose, then the cost and policy caveats, with no filler sentences. The inline enumeration of all ten markets duplicates the enum already in the schema, making the first sentence longer than needed.

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?

Given an output schema exists, the description need not detail return values, yet it voluntarily describes row structure and the over rate. Filters (player, market, dates, bookmaker) are covered by the schema, and cost limits are stated. Pagination is handled only in the schema's limit description, which is adequate but not reinforced here.

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%, so the schema already documents every parameter, including the plain-language market enum mapping and the bookmaker median-vs-single-book semantics. The description restates the market list and the median/single-book distinction without adding new format or constraint detail beyond the schema, so the baseline 3 applies.

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 states a specific verb and resource — see how a player performed against his prop line over time — and enumerates the markets and the row contents, which makes the historical nature of the tool clear. It stops short of naming a sibling (e.g. get_player_props for current lines), so the agent must infer the distinction from context rather than being told.

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 to see how a player did against his prop line over time" gives a clear usage context, and the credit cost plus 200-game cap hint at when it is worth calling. No explicit when-not-to-use or named alternative is provided, so routing against get_player_props or get_line_movement is left to inference.

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