Live game player data

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered; the description adds the non-obvious prerequisite that a match must be in progress (port 2999), which the schema does not convey. It stops short of describing the returned payload, so it is not fully complete.

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, front-loaded with purpose, then routing guidance, then the prerequisite. No filler or redundancy.

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 single-param read tool with no output schema, the description covers purpose, the sibling boundary, and the in-match prerequisite. It enumerates the returned stat categories but not the response shape, leaving a small gap that keeps it below 5.

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?

Only one parameter and schema coverage is 100%, so the schema already explains the summoner-name/local-player default. The description restates the same optional-name semantics without adding format or syntax detail, matching the baseline for a fully documented 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?

Specific verb ('fetch') plus resource ('real-time live match statistics, item inventory, abilities, and runes') for a scoped subject (local player or named summoner). It is clearly distinguishable from lol_game_all because the description names the alternative 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?

States when to use it ('to inspect a specific player's current gold, level, KDA, items, or rune setup during an active match') and when not to ('For all players in the match at once, use lol_game_all instead'). The alternative sibling is named with the selecting condition.

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