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

Annotations already declare readOnly/idempotent/non-destructive, so the description's job is to add context — and it does: explicit 10-credit cost, and the fact that win probability is only available from 2019 onward. It does not disclose default row counts or pagination behavior, but the cost and data-availability caveats are genuinely useful additions.

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?

Two dense sentences, front-loaded with the use case, then the returned fields, then filters, then cost. Every clause carries information; nothing is repeated from the schema.

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 an output schema present, the description needn't explain return values, yet it usefully previews the key ones (base-out state, batted ball, WPA, RE24). Cost and data-era caveats are included. Only pagination/default-limit behavior is left uncovered.

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?

Despite 50% schema coverage over 12 params, the description maps most of them semantically: risp, result, inning, batter/pitcher/team scopes and season. It adds the useful note that season is ignored with game_id. Limit/offset pagination params remain unexplained in the description.

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?

Names a specific resource (plate-appearance play-by-play) and enumerates its scopes: a full game in order, or a batter's/pitcher's/team's season. This clearly separates it from pitch-level siblings like get_pitches and aggregated ones like get_team_stats.

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?

"Use for plate-appearance play-by-play" plus the enumerated scopes gives a clear selection context. It never names a competing sibling or states when not to use it (e.g., pitch-level detail → get_pitches), so it falls short of a full when/when-not treatment.

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