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

Annotations only cover the read-only safety profile, yet the description adds real behavioral context: a concrete 10-credit cost model, a free estimate_only path, closing-line-as-default versus opening, and explicit policy constraints on stake/payout advice. This is meaningful disclosure beyond the structured fields.

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?

It leads with what the tool returns and its scope, then usage modes, cost, default snapshot, and policy limits, with no filler. The single long first sentence is dense but every clause adds a filter or market the agent needs.

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?

An output schema exists, so return values need not be described. Given that, the description covers markets, books, usage patterns, cost, snapshot default, and usage policy comprehensively enough for correct invocation.

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 the baseline is 3. The description goes further by explaining the interplay between game_id and player_id+season and the per-game credit charge, which the schema does not state. It stops short of enumerating every optional filter, so a 4 is appropriate.

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: player prop lines by sportsbook, enumerating six exact markets and naming the seven covered books and the 2023 season. This is far more specific than the name alone. It does not explicitly differentiate itself from close siblings such as get_prop_history or get_odds, so it stops short of a 5.

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?

It clearly describes the two usage modes: game_id for every player's props in one game, or player_id with season for one player across a season. It also flags estimate_only as the way to preview price without being charged. No alternatives (e.g. get_prop_history) are named, so it lacks the explicit routing a 5 requires.

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