account_by_riot_idRiot ID → account/puuid.
| Name | Required | Description | Default |
|---|---|---|---|
| region | Yes | americas | europe | asia | |
| tag_line | Yes | ||
| game_name | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| puuid | No | Player UUID | |
| tagLine | No | Riot tag line | |
| gameName | No | Riot game name |
Changes observed during successful MCP inspections.
Input schema / examplesAdded value: +[
+ {
+ "game_name": "Doublelift",
+ "region": "americas",
+ "tag_line": "NA1"
+ },
+ {
+ "game_name": "Caps",
+ "region": "europe",
+ "tag_line": "EUW"
+ }
+]Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "gameName": {
+ "description": "Riot game name",
+ "type": "string"
+ },
+ "puuid": {
+ "description": "Player UUID",
+ "type": "string"
+ },
+ "tagLine": {
+ "description": "Riot tag line",
+ "type": "string"
+ }
+ },
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds no behavioral context beyond the annotations, such as error handling, rate limits, or authentication needs. It is a missed opportunity to add value.
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?
The description is extremely concise (4 words), which is good for brevity but lacks structure. It front-loads the purpose but omits any elaboration. It earns its place but could be expanded slightly for clarity.
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?
Given the presence of an output schema, the return values are covered. However, the description does not mention what happens when the Riot ID is not found, any prerequisites (e.g., valid region), or the relationship to other tools. Incomplete for a tool with 3 parameters.
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 only 33%, yet the description does not clarify the 'tag_line' and 'game_name' parameters beyond the schema. The description does not compensate for the low coverage; it simply omits any parameter details.
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 'Riot ID → account/puuid.' clearly indicates the tool converts a Riot ID to an account/puuid. The verb is implied (convert/resolve), and the resource is specific. It distinguishes from the sibling 'account_by_puuid' which likely does the reverse.
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?
No guidance on when to use this tool versus alternatives like 'account_by_puuid'. The description does not mention any prerequisites, limitations, or preferred contexts. The agent is left to infer usage from the name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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