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

Annotations cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), and the description adds genuinely useful context beyond them: the shift-chart data source, a completeness check against play-by-play, cost (10 credits per game, 10 per game for a date query), and the 2010-11 onward data boundary. It stops short of describing response shape or failure behavior.

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 purpose and primary output list are front-loaded in the first sentence, and cost/coverage details are pushed to the end. It is dense and the middle clause runs long, but almost every clause carries information an agent needs.

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?

With an output schema present, return values need no further explanation, and the description still covers provenance, credit cost, data-range limits, and the optional per-player expansion. Nothing material for correct invocation 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 game_id, date, and include_players are already documented. The description reinforces that include_players adds per-skater time by strength and that date and game_id are alternatives, but adds no syntax or constraint detail the schema lacks, so the 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?

The description opens with a specific verb and resource ('exact time at each strength') and enumerates the concrete outputs — 5v5, 5v4, 4v5, 4v4, 6v5, even/PP/SH totals, period lengths — so an agent can distinguish it from get_shifts, get_plays, and get_game_detail without opening any 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?

It states the calling context ('Use for exact time at each strength') and gives the two mutually exclusive invocation modes: one game by game_id or every game on a date. It does not explicitly name a sibling to prefer or exclude, but the scope and the 'from the shift charts' provenance make the appropriate use clear.

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