Strong domain-specific tool design with clear naming (verb_noun pattern), comprehensive parameter descriptions, and well-documented schemas. All 7 tools have explicit descriptions and input schemas with type definitions. Output schemas are documented via .to_dict() returns. However, error handling lacks recovery guidance (e.g., 'unknown rule id' returns bare error dict without suggesting list_rules), and some parameter descriptions could be more prescriptive about format constraints. No tool annotations (readOnlyHint, etc.) despite all being read-only operations. Composition is excellent, tools are single-responsibility and chain well (list_rules → compute_deadline). Naming is consistently strong (list_rules, compute_deadline, working_days_between, etc.).

• Add readOnlyHint=true to all 7 tool definitions via @mcp.tool(readOnlyHint=True) to signal immutability and enable client optimizations.
• Enhance error responses: return {'error': 'unknown rule id {rule_id!r}; call list_rules() to see valid ids'} instead of bare error dict. Include actionable next steps.
• Document output schemas explicitly in tool docstrings. E.g., 'Returns: {"id": str, "kind": str, "description": str, ...}' for list_rules.
• Add JSON Schema pattern constraints for date/time inputs: 'trigger_date': {'type': 'string', 'pattern': '^\d{4}-\d{2}-\d{2}$', 'description': 'ISO date (yyyy-mm-dd)'}.
• Document deemed_receipt_date parameter interdependencies in the tool docstring: 'cutoff (HH:MM) applies only to email/portal methods; non_working_day_defers and roll_to_working_day are mutually exclusive.'