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

Adds real value beyond annotations: the Ultra-plan entitlement requirement with 403 behavior for lower tiers, the exclusion of Affiliate 27, the embedded `live_game_state` snapshot on live payloads, and the metering/no-retry constraints. Annotations already declare read-only/idempotent safety, so the extra access and entitlement context is the genuinely useful addition. Loses a point only because pagination/delay mechanics are left to the schema.

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 and useful, but the second half drifts into generic legal/usage boilerplate ('No wagers, account changes or guarantee of returns', 'Affiliate 27 is excluded') that is not directly actionable for invoking this specific read-only tool, diluting the useful entitlement info.

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?

Given an output schema exists, return-value detail is appropriately delegated. The description covers entitlement, live vs completed events, companion endpoint, and streaming alternative. It is nearly complete for an agent to call correctly, with only minor pagination experience detail missing.

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 0%, so the description must compensate. It does implicitly via the play-level result shape (sequence ordering implied by the timeline and last-plays selection), but `before_sequence` cursor and `limit` behavior are only defined in the schema. The mention of the `event_id` field convention (in the schema) is not repeated, so the description adds moderate rather than full param value.

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?

Specific verb (Get) + resource (play-by-play for an event), with the content enumerated: one entry per play with description, period, game clock, running score, and players. Distinguishes itself from stats/markets/odds siblings by describing the play-level timeline granularity.

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 two meaningful routing signals: the `live_game_state` companion endpoint, and the `plays` WebSocket channel alternative. It also warns that an empty result must not be interpreted as coverage. However there is no explicit when-not-to-use statement and no guidance on whether to prefer this over v2GetStatsByEvent or v2GetPlayerStatsByEvent for related needs, so it is implied rather than prescriptive.

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