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 is covered. The description adds useful context that chart playback and CSV export are handled elsewhere, but does not describe pagination behavior or the nature of returned rows beyond the output schema's coverage. Adds some value but not rich behavioral context.

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?

Four sentences, all earning their place: purpose first, then filters, then routing to siblings, then format exclusions. Front-loaded and free of padding, though the format-exclusion sentence is somewhat tangential.

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 12 optional parameters, full schema coverage, and an output schema, the description covers what the tool returns and how to route to siblings. Nothing critical for correct invocation is missing, though it could say more about default behavior when no filters are supplied.

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 the schema already documents all 12 parameters with defaults, ranges, and allowed values. The description restates the filter categories (game type, season range, minimum opportunities, team/stint, sort, pagination) but adds no syntax or meaning beyond the schema. 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 Catcher Blocking rows) and enumerates the scope of what rows can be returned (catchers, pitchers, catching teams, league totals). It names the sibling mlb_statcast_catcher_blocking_details, letting an agent distinguish the summary tool from the event-detail tool without opening 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?

Explicitly routes the agent: use mlb_discovery for exact values and mlb_statcast_catcher_blocking_details to expand row play-location events. It also notes 3D chart playback and CSV export are separate formats. It lacks an explicit when-not-to-use statement, so it's clear context rather than full conditional routing.

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