Three tools with basic schemas and descriptions, but significant gaps in parameter documentation, error handling, and output schema clarity. Tool names follow verb_noun convention (query, list_databases, list_tables), which is good. However, descriptions are minimal (10-40 chars), parameter descriptions are sparse or missing, and no output schemas are documented. The 'query' tool accepts arbitrary SQL with no validation guidance, creating security and usability risks. No error recovery guidance, no pagination support for list tools, and no indication of what fields are returned.

• Document output schemas for all three tools. E.g., list_databases returns [{name: string, engine: string, tables_count: number}]. list_tables returns [{name: string, engine: string, rows: number}]. query returns {data: any[], rows_read: number, elapsed_ms: number}.
• Expand 'query' description to 100-150 chars: 'Execute a SQL SELECT query on ClickHouse. Returns rows as JSON. Supports SELECT, SHOW, DESCRIBE. DDL/DML not allowed. Queries timeout after 30s. Syntax errors return the error message.'
• Add limit and offset parameters to list_databases and list_tables. E.g., limit (1-1000, default 50), offset (0+, default 0). Return total_count in response for pagination.
• Add parameter descriptions: 'query' → 'SQL SELECT statement (max 10000 chars, no DDL/DML)'. 'database' in list_tables → 'Database name to list tables from. If omitted, uses the configured default database.'
• Add error handling: 'If query fails with syntax error, the error message is returned. If timeout (>30s), retry with a simpler query or add LIMIT. If permission denied, check your ClickHouse user role.'