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

Annotations already cover read-only and idempotency, and the description adds substantial context beyond them: paid-plan gating, a concrete 25-credit cost, that an empty slate and a failed call are free, and a hard 'tonight's slate only' scope. That is exactly the operational detail an agent needs before spending credits.

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 gating constraint and purpose, and nearly every sentence carries information (scope, cost, exclusions). It runs long and the per-line distribution methodology (Poisson vs. model goal distribution) is more detail than most callers need, which keeps it off 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?

An output schema exists, so return-value explanation is not required. Given the two optional filters, the credit cost, the plan gating and the slate restriction, an agent has everything needed to decide and call 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 both filters are already documented with examples and semantics. The description restates them ('team either side of the game', 'player name fragment') and adds the explicit 'optional' framing, but contributes no format or edge-case detail beyond the schema. 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 and resource: model-projected stat lines for tonight's NHL skaters and goalies, with named fields (goals, assists, points, shots, saves). It also draws a clear boundary against get_player_props/get_odds by declaring 'Numbers only: no odds, prices or injury notes.' An agent can pick this over its siblings without opening a schema.

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?

Gives explicit when-to-use (projected stat lines for tonight's slate) and when-not (no odds, no injury notes, no date argument, paid plans only). It does not name the alternative sibling tools such as get_player_props or get_predictions directly, so the routing is inferred rather than spelled out.

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