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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds useful content-level context (composite rankings, per-card top five players, embedded links) and notes the live season selector, but with an output schema present it does not need to detail return structure further.

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 tight sentences: the first front-loads purpose and return contents, the second handles the season selector and the alternative-tool routing. No wasted phrasing.

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 single-optional-parameter read tool with an output schema and readOnly/openWorld annotations, the description covers purpose, contents, and when to prefer other tools. Nothing essential to calling it correctly is missing, though a named sibling would make routing airtight.

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?

Only one parameter (year) and schema description coverage is 100%, with the schema itself pointing to mlb_discovery.statcast_top_performers_years for valid values. The description's mention of the 'live season selector' adds only marginal 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?

States a specific verb (Fetch) and resource (Baseball Savant's composite Top Performers rankings for a season), then enumerates exactly what is returned (batter/pitcher cards, top five players, values, profile and leaderboard links). It also distinguishes itself from the crowded mlb_statcast_* sibling set by routing full filtered tables elsewhere.

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 says to use specialist mlb_statcast tools for full filtered tables, which tells the agent when NOT to use this tool. It does not name a specific sibling, so the routing is directional rather than exact, but the context is clear.

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