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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety needs no restating. The description adds context the annotations cannot: the exact return payload (games, times, scores, probabilities, starters, injury deltas). It does not mention volume, pagination or how live scores refresh, which is the only remaining gap.

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?

Three sentences, front-loaded with the trigger condition, followed by return contents and then the routing exclusion. The dense field list is informative rather than padding, and nothing is redundant.

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 burden of describing results and does so explicitly, plus league scoping and date optionality via the schema. For a two-optional-parameter read tool, an agent has everything needed to call it and interpret the response.

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% and both parameters are already documented, including the enum and the YYYY-MM-DD format, so the baseline is 3. The description reinforces the date semantics with a worked example and implies omitting the date yields the current slate, but adds no syntax or behavior not already in the schema.

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 names a specific resource (a day's slate of games) and enumerates what comes back: game_id, US Eastern times, live/final scores, win probabilities, starters and injury changes. It also differentiates itself from the sibling find_game, so an agent can pick between them without inspecting either 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?

It states the triggering user intents ('what is on tonight', 'today's scores', 'a given day's games') with a concrete date example, and gives an explicit exclusion plus the alternative: not a game weeks away or a single team's schedule — use find_game. Both the when and the when-not are present.

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