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

Beyond the readOnly/openWorld annotations, the description discloses genuinely useful behavior: sample size on every row, a two-season lookback window, Kalshi prop prices shown alongside, questionable players forking into plays/sits branches, and the explicit 'no projection' caveat. This is rich context an agent could not infer from 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?

Front-loaded with the 'Use for...' trigger phrases and dense with information; nearly every clause earns its place. It is a long single paragraph rather than cleanly segmented, which keeps it from a 5.

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?

With no output schema, the description carries the return-value burden well: it explains that each absent star yields beneficiary rows with per-row sample sizes and side-by-side Kalshi prices, and notes the plays/sits branch behavior for questionable players. An agent knows what it will get back.

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 all four parameters are already documented in the schema. The description echoes the stat concepts (minutes, points, rebounds, assists, usage) but adds no format or default guidance beyond what the schema provides, 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?

States a specific verb+resource: NBA absences from the official injury report plus the teammates whose stats rose without the absent star. The example queries ('Embiid's out tonight — who benefits?') make the intent unmistakable and distinguish it from prop/game board siblings.

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 'Use for...' framing plus two concrete example questions give clear when-to-use context, and 'Historical splits only, no projection' sets a boundary. It never names a sibling alternative (e.g. nba_prop_board) explicitly, so it falls short of a 5.

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