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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile (read-only, external data) is covered. 'Fetch ... rows' is consistent with that. The description adds little beyond the annotations — no mention of pagination, default row behavior, or result limits — so a 3 is warranted given annotations carry the behavioral load.

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 tight sentences with zero filler; the core purpose is front-loaded and the routing hint ('use mlb_discovery') is placed last as a secondary pointer. Every clause earns its place.

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?

For a 25-parameter tool with full schema coverage, an output schema, and annotations covering the safety profile, the description gives enough framing (purpose, filter surface, discovery pointer) for correct invocation. It does not clarify the swing_timing_details sibling relationship, which is the one remaining gap.

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 every one of the 25 parameters is already documented, including documented value enumerations and defaults. The description only lists filter categories generically and adds no syntax or format detail beyond the schema, so the 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 (Fetch) and resource (Baseball Savant Swing Timing and Miss Distance rows) and names the entity types it can return (batters, teams, pitchers, league totals). It is clear, but it does not distinguish itself from the sibling mlb_statcast_swing_timing_details, which an agent would need to tell apart.

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 clear context by enumerating the filter dimensions available (season, game type, split, team, date, pitch, count, timing axis, threshold) and explicitly routes the agent to mlb_discovery for exact parameter values. No explicit when-not conditions are provided, but the contextual guidance is solid.

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