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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds context the annotations cannot: a concrete cost of 5 credits and an upstream dependency on search_players. It does not discuss error behavior for invalid player IDs, which keeps it below 5.

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?

Three tight sentences: trigger condition first, then return contents split by position, then prerequisites and cost. Every sentence carries information an agent needs, with no filler or repetition of the title.

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, the description need not enumerate return fields, yet it still summarizes the notable skater and goalie metrics. Combined with the credit cost and the prerequisite tool call, an agent has everything needed to decide and invoke correctly.

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 100%, so both parameters are already documented and the baseline is 3. The description earns a bump by specifying the provenance of player_id via search_players, adding meaning the schema text ('NHL player ID') does not convey; the league parameter and its default are left entirely to 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?

States a specific verb-and-resource (full details for one player) and enumerates exactly what is returned for skaters versus goalies, which lets an agent predict the payload shape. It never explicitly distinguishes itself from the closely overlapping siblings get_skater_season_stats and get_goalie_stats, so it stops short of a top score.

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?

'Use when you need full details for one player' sets a clear triggering condition, and 'Requires player ID from search_players' names the prerequisite tool that produces the required input. It gives no when-not-to-use guidance or comparison against the per-league stats siblings, so the routing is incomplete rather than ambiguous.

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