Server has 4 well-defined tools with complete input schemas and descriptions. All tools are READ_ONLY and follow verb_noun naming (hero_stats, pro_matches, search_players, get_player). Descriptions are clear and mention OpenDota's keyless/rate-limited nature. However, output schemas are not documented, LLMs cannot predict response structure. Parameter descriptions are minimal (e.g., 'Max heroes to return' lacks context on when to use). No error recovery guidance beyond rate-limit handling. Missing tool annotations (readOnlyHint). Role filtering in hero_stats lacks enum constraint, inviting hallucinated values.

• Add output schema documentation to each tool. Example for hero_stats: 'Returns {count: number, heroes: [{id, name, primary_attr, attack_type, roles, pro_pick, pro_win, pro_ban}]}'.
• Convert hero_stats 'role' parameter to an enum: ['Carry', 'Support', 'Initiator', 'Durable', 'Nuker', 'Disabler', 'Escape', 'Pusher', 'Jungler'] based on Dota 2 role taxonomy.
• Add readOnlyHint: true to all tool schemas to signal safety to LLMs and enable optimizations (caching, parallel execution).
• Enhance error messages with recovery guidance: 'OpenDota rate limit (60 req/min). Wait 30s or try a simpler query (e.g., fewer heroes or matches).'
• Expand parameter descriptions with context: 'limit: Max heroes to return (default 30, max 150). Increase to see more meta picks; decrease to focus on top picks.'