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 real behavioral context beyond that: the Bat-side R/L sub-selector was verified as a no-op and is deliberately not exposed, which prevents the agent from trying to filter on it, plus it notes pagination is local.

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 verb and resource before the supporting detail. The parameter inventory sentence is somewhat dense and list-like, but nothing is padded or repeated.

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 present and annotations covering the read-only profile, the description need not explain return values, and all 11 params are documented. The only shortfall is the absence of sibling routing (e.g. vs fielding run value), which is a minor gap rather than a blocking one.

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 parameter (defaults for min, year, group, leverage, limit; ranges for limit/offset) is already documented in the schema. The description only re-lists the parameter categories and adds no syntax, format, or interaction detail, so the baseline of 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 and resource ('Fetch Baseball Savant batting or pitching Run Value rows') and enumerates the selectable dimensions (year, team, min PA, leverage, table type, subtype, sorting, pagination). Saying 'batting or pitching' implicitly separates it from the fielding-run-value sibling, but it never names that sibling, so the differentiation is left partly to inference.

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?

Provides one explicit routing rule ('Use mlb_discovery for valid values'), which is genuinely useful for the enum-less string params. However it gives no when-to-use/when-not guidance relative to alternatives such as mlb_statcast or mlb_statcast_fielding_run_value, so the agent must infer selection from the resource name alone.

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