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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety profile is covered. The description adds useful structural behavior (catcher rows expand via the details tool) but says nothing about pagination behavior, rate limits, or result shape beyond what the output schema supplies.

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 resource and scope, then the filter list and dependency routing. Every clause maps to a real capability; the filter enumeration is long but not 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 an output schema and fully documented 13-parameter schema, the description supplies what an agent needs: scope, filter axes, and the two sibling tools for value discovery and row expansion. Only the absence of guidance relative to near-identical catcher statcast tools leaves a small 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 coverage is 100% with per-parameter descriptions and defaults, so the schema carries parameter semantics. The description only restates the filter categories (season range, game type, minimum, target base, etc.) without adding format or interaction details such as how team/split/with_team_only combine.

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 a precise resource ('Baseball Savant Catcher Throwing rows') and enumerates the three row scopes (catchers, catching teams, league totals), which separates it from generic statcast endpoints and from catcher_blocking/framing siblings. It does not explicitly contrast those siblings, keeping it short of a 5.

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 explicit routing guidance: use mlb_statcast_catcher_throwing_details to expand catcher-level rows, and mlb_discovery to resolve exact parameter values. It does not state when to prefer this over catcher_framing/blocking/pop_time, so it stops just short of full when/when-not coverage.

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