summoner_by_puuidFetch LoL summoner details (summoner ID, account ID, summonerLevel, profileIconId, revisionDate) for a puuid on a specific platform (e.g. na1, euw1).
| Name | Required | Description | Default |
|---|---|---|---|
| puuid | Yes | ||
| platform | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| id | No | Summoner ID | |
| name | No | Summoner name | |
| puuid | No | Player UUID | |
| accountId | No | Account ID | |
| profileIconId | No | Profile icon ID | |
| summonerLevel | No | Summoner level |
Changes observed during successful MCP inspections.
Input schema / examplesAdded value: +[
+ {
+ "platform": "na1",
+ "puuid": "player-puuid-123456"
+ }
+]Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "accountId": {
+ "description": "Account ID",
+ "type": "string"
+ },
+ "id": {
+ "description": "Summoner ID",
+ "type": "string"
+ },
+ "name": {
+ "description": "Summoner name",
+ "type": "string"
+ },
+ "profileIconId": {
+ "description": "Profile icon ID",
+ "type": "number"
+ },
+ "puuid": {
+ "description": "Player UUID",
+ "type": "string"
+ },
+ "summonerLevel": {
+ "description": "Summoner level",
+ "type": "number"
+ }
+ },
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already provide readOnlyHint, idempotentHint, openWorldHint, destructiveHint=false. Description adds value by specifying the exact fields returned, which is not in annotations. No contradictions.
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?
Single sentence, front-loaded with key information, no unnecessary words. Extremely concise and easy to parse.
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 simple fetch tool, description covers required inputs and returned fields. Output schema exists to detail return values. Could mention platform format or validation, but overall adequate.
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 0%, so description must compensate. It mentions 'puuid' and 'platform' and gives example 'na1' but does not explain what puuid is or list valid platform values. Minimal additional meaning.
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?
Description clearly states verb 'Fetch', resource 'LoL summoner details', lists specific fields (summoner ID, account ID, summonerLevel, profileIconId, revisionDate), and specifies key parameters (puuid, platform). It differentiates from siblings like account_by_puuid by focusing on summoner details.
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?
Description implies usage context (for a puuid on a specific platform) but does not explicitly state when to use this tool versus alternatives (e.g., account_by_puuid, match_ids_by_puuid). No when-not or alternative guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.