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 genuinely non-structured context: a credit cost and the fact that partial-name matching is supported. It stops short of saying whether multiple matches are returned or how ties are ordered.

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?

One sentence, zero waste, with the matching behavior front-loaded and the cost disclosure appended. Nothing redundant with the title or annotations.

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 return values needn't be explained, and the credit cost is a nice addition. But for a search tool the crucial missing piece is result-set behavior — multiple matches, limit default, league scope — which the description leaves to the schema alone.

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?

With 67% schema coverage, the baseline is 3. The description reinforces the name parameter (partial names work), which is useful, but adds nothing about the limit cap of 50 or how the league enum interacts with name matching.

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?

Names a specific verb and resource (find a player's id), plus the key affordance that partial names work. This separates it from sibling get_player, which clearly implies lookup by known identifier. An agent can pick the right tool 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 to find a player's id by name" gives the triggering condition, so usage is implied rather than spelled out. It never states when not to use it or routes the agent to get_player once an id is known, nor does it mention the league/limit trade-offs between results.

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