Server has 6 well-named, read-only tools with consistent verb_noun naming (search_, get_). All tools have descriptions (avg 140 chars, within baseline 34-392). Input schemas are present with Pydantic Field descriptions. However, output schemas are NOT documented, responses are inferred from code inspection only. Parameter descriptions lack format constraints (e.g., date format YYYY/MM/DD is stated but not enforced via regex or enum). No error handling guidance, no pagination support despite tools returning potentially large datasets, and no indication of result limits. Missing tool annotations (readOnlyHint present implicitly via Risk field, but not in MCP schema). Date parameters accept free-form strings with no validation.

• Add formal output schemas to each tool definition. Use JSON Schema to document the structure of 'records' array, field types (e.g., volume: number, price: number, date: string), and any nested objects. This enables LLMs to extract and chain results reliably.
• Enforce date format validation. Add a regex pattern to start_date parameters: '^\d{4}/\d{2}/\d{2}$' or use a custom validator that rejects malformed dates with a clear error message like 'Invalid date format: expected YYYY/MM/DD, got {value}'.
• Document and enforce result limits. Update tool descriptions to state 'Returns up to 50 results' or 'Returns all records (typically 100-500 per month)'. Add a limit parameter to get_daily_trades, get_weekly_trades, get_monthly_trades with default=50, max=500.
• Add error recovery hints. Wrap api_get() calls in try-except; on 404 or invalid item_code, return a structured error like '{"error": "Item code not found", "suggestion": "Call search_products(keyword=...) to find valid codes"}' instead of raw API errors.
• Expose readOnlyHint in MCP tool definitions. Update FastMCP tool registration to include readOnlyHint=True for all six tools, enabling clients to render read-only badges and prevent accidental misuse.