Single tool with complete JSON Schema and detailed parameter constraints (enums, oneOf). Description is comprehensive (240+ chars) and explains use cases. However, output schema is undocumented (returns CSV text, not structured fields), and error handling lacks recovery guidance. Parameter descriptions are present but some are minimal (e.g., 'city_district' has no format hints). No tool annotations (readOnlyHint, etc.). Naming is clear (search_military_companies) and follows verb_noun pattern.

• Document output schema explicitly. Instead of returning raw CSV, return structured JSON with fields: [{ company_name, industry_sector, company_size, location, hiring_status, service_types_available }]. Include total_count and next_cursor for pagination.
• Add pagination support. Accept limit (default 20, max 100) and offset/cursor parameters. Return total_count so LLM knows if more results exist.
• Enhance error messages with recovery guidance. E.g., 'Invalid service_type: got "invalid". Must be one of: 산업기능요원, 전문연구요원, 승선근무예비역. Try again with a valid type.' Categorize errors as retryable vs. fatal.
• Add readOnlyHint annotation to tool definition to signal that this tool does not modify state and is safe to call multiple times.
• Constrain city_district parameter with a pattern or validation. Document expected format (e.g., '2-4 Korean characters') or provide a discovery tool to list valid districts per city_province.