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

Beyond the readOnlyHint annotation, the description discloses important defaults and fallback behavior ('returns current-season players by default, falling back to all players back to 1999 when none match'), data-coverage scope, cost (2 credits), and the returned id's role. This is meaningful behavioral context not present in the structured fields.

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: purpose, scope/defaults, and downstream value/cost. No filler, front-loaded with the actionable verb, and every clause carries information an agent needs before calling.

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 search tool with well-documented parameters, a read-only annotation, an output schema, and a sibling context, this description covers all essentials: what it searches, defaults, fallback, output linkage, and cost. 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% and each parameter already has a clear description, so the baseline is 3. The tool description reinforces the query semantics with 'partial match' but does not add meaning beyond what the schema states for individual parameters.

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 and resource: 'find a player by name (partial match)' and immediately names the downstream purpose ('GSIS player id needed by get_player_stats'). It also scopes the data domain (25,000 players back to 1999), making it unambiguous how this differs from stats/game/roster siblings.

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 makes the intended context clear — use it to locate a player and obtain their GSIS id before calling get_player_stats. It does not explicitly enumerate when not to use it or name competing lookup tools, so it falls just short of a 5, but the downstream linkage provides strong situational guidance.

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