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

Annotations already declare readOnlyHint and openWorldHint, so the bar is lower. The description adds real value beyond them by scoping the output ('statistical rows only, not media, graphics, or CSV'), which disambiguates the tool from the graphics/CSV views of Statcast pages, and by flagging the live-season date constraint.

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?

The core purpose leads the sentence and is followed by constraints and return-scope in a compact three-clause structure with no filler. Minor looseness in 'first-party filters' keeps it from a 5.

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 detailed, and the description still clarifies the row-only nature of the response. Combined with 100% schema coverage and annotation safety hints, an agent has enough to invoke this tool correctly; only explicit sibling routing 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%, so the schema already documents all eight parameters with defaults and ranges. The description only restates the categories of parameters (type, min games, active-player, sort, pagination) without adding syntax or format meaning beyond the schema, so 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?

The description states a specific verb and resource: fetch Statcast birthday tables (batters, pitchers, and the upcoming-birthday table). This clearly conveys what the tool returns. It does not explicitly differentiate itself from any sibling, though no sibling covers birthdays, so disambiguation is implicitly adequate.

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?

It supplies a meaningful constraint ('date must be within the live season range') and frames type/min-games/show-inactives/sort/pagination as filters, which implies usage context. However, it never states when to choose this tool over another or any when-not condition, leaving routing to inference.

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