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 usefully discloses the external dependency on mlb_discovery for valid filter values, but says nothing about defaults, pagination limits, or what the returned rows represent beyond the filter list.

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 dense, front-loaded sentences that lead with the resource and end with the discovery pointer. The mid-sentence filter enumeration is a bit list-heavy but every element maps to a real parameter, so nothing is wasted.

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 an 18-param, all-optional read tool with a full output schema and safety annotations, the description covers the resource, entity types, and the mlb_discovery routing hint. An agent has enough to call it correctly; only the cross-sibling differentiation 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 every one of the 18 parameters is already documented in the schema. The description only names filter categories (seasons, game type, knee posture, etc.) without adding syntax or constraints beyond what the schema provides, 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 Catcher Stance rows') and enumerates the row/entity types the table covers (catchers, catching teams, batters, batting teams, pitchers, league totals). This is enough to distinguish it from the many sibling statcast tables by resource name, though it never explicitly contrasts itself with close siblings like mlb_statcast_catcher_framing.

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 one clear routing hint is 'use mlb_discovery for exact values', which tells the agent where to resolve filter values. However, there is no guidance on when to choose this table over the other catcher statcast tools, nor any exclusions or prerequisites.

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