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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds genuine non-obvious behavior: the upstream query's hidden All-Star game type A acceptance, which the schema lists but does not flag as unusual. No auth, rate-limit, or pagination-disclosure details beyond that.

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 tight sentences: what it fetches, how to filter, and one caveat. The row-type enumeration is front-loaded and nothing is padded.

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 18 fully-described params and an output schema, the description need not explain returns, and it correctly covers scope, filtering, and the discovery lookup path. It is complete enough to call correctly, though it gives no sense of data volume or the distinction from other statcast siblings.

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% with defaults for min, type, seasons, game_types, and split_year already documented. The description's filter keyword summary (season, game type, split, team, date, hand, pitch type, BBE thresholds, sort/page) mostly restates the schema; the only added value is the mlb_discovery lookup pointer.

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 (Fetch), a specific resource (Baseball Savant Batted Ball Profile rows), and enumerates the five row types it returns (batter, batting-team, pitcher, pitching-team, league). An agent can distinguish this from other mlb_statcast_* tools by the resource name alone.

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?

Explicitly routes the agent to mlb_discovery for exact parameter values, which is a concrete when-to-use-which-tool instruction. It stops short of naming when to prefer this over sibling statcast tools (e.g. pitch arsenal, expected stats), so it is clear context without full alternatives coverage.

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