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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely non-structured context: dataset size and temporal coverage (4,800+ players since 2010-11), the default filtering behavior (active only, active=false for retired/historical), and a cost signal ('Costs 2 credits'). It doesn't discuss rate limits or result-shape, but with an output schema present that is minor.

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?

Five short sentences, each earning its place: trigger, scope, default behavior, next-step workflow, and cost. The most important information (when to use it) is front-loaded and there is no filler.

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 6-parameter search tool with an output schema and safety annotations, the description covers triggers, defaults, dataset scope, cost, and the chained workflow, so an agent has enough to call it correctly. Minor gaps remain around pagination/limit behavior and empty-result handling, but nothing critical 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% with 6 documented parameters (including enum lists for league and position), so the schema carries the parameter burden. The description only re-states the active default and partial-match searching for query, adding no syntax or format detail beyond the schema; baseline 3 is correct here.

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 ('looking up a player by name', 'Searches 4,800+ players across every season since 2010-11') and implicitly separates the discovery role from retrieval tools by directing the agent to get_player_stats for details. An agent can distinguish it from get_player_stats without opening either 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?

'Use when looking up a player by name' is a clear trigger, and the follow-up instruction ('Use the returned player ID with get_player_stats') gives explicit workflow routing to the sibling tool. It lacks an explicit when-not (e.g., 'if you already have a player ID, call get_player_stats directly'), so it stops just short of full routing guidance.

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