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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safe-read profile is covered. The description adds that filters are 'live-verified' and names the filter families, but says nothing about rate limits, pagination behavior, or the difference in payload from the _details sibling; with annotations carrying safety, a 3 fits.

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 sentences, front-loaded with the subject and resource before enumerating filters. The filter list is dense but earns its space as a scannable inventory; 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?

An output schema exists, so return values need not be explained, and the 100%-covered schema documents every parameter. The description covers the resource, the filter surface, and the discovery dependency, leaving only the sibling-disambiguation 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% with enumerated documented values on nearly every parameter, so the schema does the heavy lifting and baseline 3 applies. The description goes slightly beyond by grouping the 22 params into named filter categories and pointing to mlb_discovery as the source of valid values, which marginally aids semantics.

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 First Base Receiving rows), plus the populations covered (first basemen, throwing fielders, teams, league). It does not name or distinguish itself from the near-identical sibling mlb_statcast_first_base_receiving_details, so an agent has to infer the boundary.

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?

The only real guidance is 'use mlb_discovery for exact values', which usefully routes filter-value resolution. It never says when to prefer this over mlb_statcast_first_base_receiving_details or what the prerequisites are, so usage is implied rather than stated.

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