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

Even though no annotations are provided, the description discloses key behavioral facts: the operation is read-only with no side effects, it is API-key gated and rate-limited, results are row-capped per tier, and count=0 with an empty rows array is returned instead of an error when no props exist. It also explains odds formatting (American integers, null when unavailable) and row fields such as gameState? and flashProjection? being optional. This goes well beyond a basic description, though it doesn't go into deeper side effects or failure modes beyond rate limits.

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 description is dense but well-structured: a clear lead sentence, a return-shape block, THEN when-to-use and when-not-to-use, plus exact null/empty behavior. Every sentence earns its place; the most important scope and usage routing are front-loaded.

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 a read-only, no-side-effect listing tool with 0 required parameters and full schema coverage, the description covers scope, return semantics, edge cases, and alternatives. It lacks an explicit statement of error codes or network/rate-limit failure behavior beyond mentioning rate-limited, but given the simple parameter surface and no required params, this is complete enough for an agent 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 description coverage is 100%, so the input schema already documents all three parameters. The description reinforces the tier limit and default behavior (omit limit to use tier maximum; omit sport to use current in-season sport), but it doesn't add a lot of novel parameter detail beyond what the schema provides. Baseline 3 is appropriate when schema carries the heavy lifting.

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 an explicit action (Flatten/scan), a precise resource (all active player props across all of today's games for a sport), and a clear output shape. It differentiates itself from siblings like get_game_props and find_player_props by naming them, and even frames itself as a market-wide broad view, so an agent can clearly tell what this tool is for.

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?

The description gives explicit when-to-use guidance ('when you need a broad cross-game market view'), explicit when-not-to-use guidance ('use get_game_props when you already have an eventId; use find_player_props for one player'), and mentions the tier limit behavior. This is very strong routing information.

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