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 only that rows can be player- or team-level; it says nothing about pagination behavior or result shape, though an output schema exists. With annotations carrying the safety burden, a 3 is appropriate.

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, purpose front-loaded before the sibling routing, with no filler. The second sentence is dense but each clause carries routing information that 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 9-parameter, all-optional leaderboard query with full schema coverage, an output schema, and read-only annotations, the description supplies what the structured fields cannot: when to pick this tool over its near-duplicate siblings. Nothing critical for correct invocation is missing.

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% and every parameter is documented in the schema itself, including allowed values. The description's filter list (season, team, position, throws, sorting, page) merely restates those dimensions without adding syntax or defaults, 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) plus the exact resource (Baseball Savant Arm Strength leaderboard rows) and its scope (players or teams, with filter dimensions). It also names the sibling tools that would be wrong choices, so the agent can distinguish it without opening a 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: use mlb_statcast_arm_strength_player for one player's throws, mlb_statcast_arm_value for the separate run-value metric, and mlb_discovery for exact filter values. Each alternative comes with the condition that selects it, leaving little to inference.

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