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

Annotations already declare readOnly/idempotent/non-destructive, so the description's job is lighter; it still adds the credit cost ('Costs 1 credit') and the accent-insensitive matching behavior, both of which are real traits not captured in 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?

Two compact sentences, front-loaded with the purpose, then scope, then return shape, then cost. 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?

An output schema exists, so the return-value sentence is redundant but harmless. Purpose, cost and the accent nuance are covered; only the undocumented 'limit' parameter and the absence of routing to get_player leave small gaps.

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 75% with documented name/team/league, so the baseline is already high; the description nonetheless adds meaning by clarifying accents are optional and that the club filter is optional rather than required.

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 ('find a player's id by name') plus the scoping options and the returned fields. It implicitly separates itself from get_player (id lookup vs. name lookup), though it never names that sibling explicitly.

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 phrase 'Use to find a player's id by name... optionally within a club' implies the lookup scenario, but there is no explicit when-not guidance and no named alternative (e.g. get_player) for the case where the id is already known.

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