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

Annotations already indicate readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds useful behavioral context by stating it 'RETURNS summary + events[]' and mentioning mode/lane behavior (e.g., spotlight defaults to tier 1). While not covering every side-effect, the annotations cover the safety profile and the description enriches the expected behavior without contradiction.

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 information-dense, using shorthand like 'HR#' and 'K#' that is likely domain-standard. It avoids unnecessary words and front-loads the core trigger condition. Minor demerit for cryptic phrasing ('roster cardology') that might confuse a general agent, but overall it is efficient and well-structured.

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?

No output schema is provided, but the description partially compensates by specifying 'RETURNS summary + events[]' and listing example pattern labels (day=HR#, HR#=jersey). It also includes an example retro_id and mode/lane defaults. This is sufficient for a read-only tool, though a full output schema would improve completeness.

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 covers all 7 parameters with descriptions (100% coverage). The prose description repeats some parameter details (mode defaults, lane defaults, limit range) but adds no new semantic meaning beyond the schema. Since coverage is complete, a baseline of 3 is appropriate; no significant extra clarity is provided by the description.

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 states the tool's purpose: retrieving play numerology when a player's season HR# or K# aligns with calendar day, jersey number, or inning. It also explicitly distinguishes from sibling tools ('NOT for roster cardology → get_team_chemistry; cosmic day card → get_date'), ensuring an agent can select it correctly without opening the schema.

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 provides explicit usage triggers ('USE when...') and exclusions ('NOT for...'), along with mode/lane defaults and a cross-tool hint ('Overlay get_date(game_dt)'). This gives clear when-to-use and when-not-to-use guidance, fully satisfying the dimension.

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