Steam MCP has 20 well-named tools with consistent verb_noun patterns (get_*, search_*, resolve_*). All tools have descriptions (avg ~120 chars, within baseline 34-392 range). Input schemas are present and typed for all tools. However, output schemas are NOT documented, critical gap per pattern:tool. Parameter descriptions are present but often minimal (e.g., 'Steam App ID of the game' lacks format/range guidance). No error handling guidance visible in tool definitions. Missing tool annotations (readOnlyHint, idempotentHint). All tools are READ_ONLY but this is not formally declared in schema.

• Document output schemas for all 20 tools. Include field names, types, and whether fields are always present or conditional. Example: get_player_summary returns {player_id: string, display_name: string, avatar_url: string, online_status: enum, currently_playing: {app_id: number, game_name: string} | null, ...}.
• Add readOnlyHint: true to all tool schemas in registration. This formally declares that all tools are safe to call without side effects, enabling agents to retry confidently.
• Enhance parameter descriptions with format/range constraints. E.g., 'country_code: Two-letter ISO 3166-1 alpha-2 code (e.g., US, BR, DE). Default: US.' and 'app_id: Positive integer Steam App ID (e.g., 570 for Dota 2).'
• Add error recovery guidance to tool descriptions. E.g., resolve_vanity_url: 'If vanity URL is invalid, returns error. Try search_apps() to find the game by name instead.' get_player_summary: 'If steam_id is invalid, returns error. Use resolve_vanity_url() to convert a custom URL first.'
• Document pagination fully. Specify offset/cursor parameters, response structure (total_count, has_more, next_cursor), and default/max limits. E.g., get_owned_games: 'Returns up to 500 games. Use limit (1-500, default 50) and offset for pagination. Response includes total_count.'