owned_gamesList all games owned by a SteamID64; optionally include app name/icon and free-to-play games. Returns appid, playtime_forever (minutes), and per-game metadata.
| Name | Required | Description | Default |
|---|---|---|---|
| steamid | Yes | ||
| include_appinfo | No | ||
| include_played_free | No |
| Name | Required | Description | Default |
|---|---|---|---|
| response | No |
Changes observed during successful MCP inspections.
Input schema / examplesAdded value: +[
+ {
+ "steamid": "76561198000000000"
+ },
+ {
+ "include_appinfo": true,
+ "include_played_free": true,
+ "steamid": "76561198000000000"
+ }
+]Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "response": {
+ "properties": {
+ "game_count": {
+ "description": "Total games owned",
+ "type": "number"
+ },
+ "games": {
+ "items": {
+ "properties": {
+ "appid": {
+ "description": "Game app ID",
+ "type": "number"
+ },
+ "has_community_visible_stats": {
+ "description": "Has public stats",
+ "type": "boolean"
+ },
+ "img_icon_url": {
+ "description": "Icon URL",
+ "type": "string"
+ },
+ "img_logo_url": {
+ "description": "Logo URL",
+ "type": "string"
+ },
+ "name": {
+ "description": "Game name",
+ "type": "string"
+ },
+ "playtime_2weeks": {
+ "description": "Last 2 weeks playtime minutes",
+ "type": "number"
+ },
+ "playtime_forever": {
+ "description": "Total playtime minutes",
+ "type": "number"
+ },
+ "playtime_linux_forever": {
+ "description": "Linux playtime minutes",
+ "type": "number"
+ },
+ "playtime_mac_forever": {
+ "description": "Mac playtime minutes",
+ "type": "number"
+ },
+ "playtime_windows_forever": {
+ "description": "Windows playtime minutes",
+ "type": "number"
+ }
+ },
+ "type": "object"
+ },
+ "type": "array"
+ }
+ },
+ "type": "object"
+ }
+ },
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the operation as read-only, idempotent, and non-destructive. The description adds meaningful behavioral details: it returns specific fields (appid, playtime_forever in minutes, and per-game metadata) and notes optional inclusions. This provides enough context beyond the safety hints, without redundancy.
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 a single, front-loaded sentence that states the core action and then adds optional parameters and return fields. Every word contributes value; there is no fluff or repetition of what annotations already state.
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?
This is a simple, read-only list tool with an output schema, so the description does not need to detail return structures. It covers the essential aspects: input (SteamID64), optional flags, and key output fields. It does not mention pagination or rate limits, but for this basic tool the description is adequately complete.
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?
Given the schema has no property descriptions (0% coverage), the description compensates well. It explains steamid via the main sentence, and the optional parameters are conveyed through 'include app name/icon' and 'include free-to-play games'. The mention of 'playtime_forever (minutes)' also adds unit context. The mappings are clear, though not explicitly named.
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 clearly states the tool lists all games owned by a SteamID64, with a specific verb and resource. It also distinguishes itself from siblings like recently_played by focusing on the full owned-game library, and optionally includes app info and free-to-play status. This makes the purpose unambiguous and differentiated.
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 primary use case is explicit: retrieve all games owned by a given SteamID64. The description also clarifies optional behaviors (including app info and free-to-play games) that adjust the query. However, it does not explicitly compare against alternatives like recently_played or friend_list, so there is no exclusionary guidance, only clear context.
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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