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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: the default view and window, the blend-window weighting mechanic ('last season counts as 20 games'), and how to interpret CF% above 50.

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?

A single dense paragraph, front-loaded with the tool's purpose and then walking through views and window, with essentially no filler. It is on the long side and could be broken into bullets, but every clause carries usable information.

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 9-parameter, no-output-schema query tool, the description covers the two ambiguous dimensions (view and window) that an agent must get right, plus metric interpretation. Remaining gaps are minor secondary filters (sort_by, position, plays_today) and pagination/return-shape details.

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 coverage is a moderate 67%, and the description meaningfully compensates: it defines the semantics of every 'view' enum value and elaborates the 'window' modes beyond the terse enum labels. It says nothing extra about sort_by, position, min_gp, limit or plays_today, but those are partly covered in the schema.

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+resource ('NHL 5v5 shot attempt stats (Corsi)') and enumerates the four view modes with the fields each returns, so an agent knows exactly what data it yields. It does not differentiate itself from nearby siblings such as invoke_nhl_lines or invoke_nhl_line_matchups, whose 'line' scope overlaps with the 'lines' view here.

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 gives the default behavior ('view games (default)') and explains what each view returns, which implicitly guides view selection, plus the meaning of window options. However, it never states when to prefer this tool over siblings or any exclusions, so usage is only implied.

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