mlb_people_changes

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

The description adds meaningful behavioral context beyond the annotations: it discloses the return structure, notes that the response 'can be large for a wide window', and explicitly states 'Auth: none needed'. These details supplement the readOnlyHint and idempotentHint annotations, giving the agent a better sense of what to expect.

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 description is compact and front-loaded: it states the core function in the first sentence, shows the return shape in a structured block, and includes a one-line auth note. Every sentence adds value without redundancy.

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?

The description covers the essential contextual elements: it identifies the tool as a sync helper, specifies the return shape (important because no output schema exists), warns about response size, and states auth requirements. It does not explicitly mention alternatives or exclusions, but for a simple polling tool with high schema coverage and strong annotations, it provides sufficient context.

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?

The input schema provides complete descriptions for both parameters (updatedSince as ISO timestamp, fields as trimming), so the description does not need to replicate that. It adds a small behavioral note about wide windows affecting response size, but does not introduce new parameter-level semantics beyond the schema. Thus, 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?

The description clearly defines the tool as a polling/sync helper for player records changed since a timestamp, which distinguishes it from sibling tools like mlb_game_changes. It specifies the resource (player records) and the operation (retrieve changes), making the purpose unambiguous.

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 description explicitly labels the tool as a 'polling/sync helper' and identifies it as the 'people-side sibling of mlb_game_changes', providing clear context for when to use it. It does not explicitly list exclusions or alternative tools, but the sibling reference and the 'changed since a timestamp' phrasing give a clear usage context.

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