FDC Property Finance MCP demonstrates solid definition quality with well-named, domain-specific tools and comprehensive parameter schemas. All 4 tools are explicitly registered with clear descriptions and proper JSON Schema input definitions. However, the server lacks output schema documentation, error handling guidance, and several tools have verbose descriptions that could be more LLM-optimized. Tool names follow verb_noun convention (run_* / calculate_*) which is appropriate for the domain. All parameter descriptions are present and include contextual UK property finance details (e.g., '2026 bridging rates typically 0.65% to 1.15% per month'). Input schemas use Zod with proper types and enums. The major gap is absence of documented output schemas, while structuredContent is returned in handler, the response structure is not declared in tool metadata.

• Document output schema for each tool. For bridging_cost_analyser, define: { headline_apr_pct: number, effective_apr_pct: number, interest_payable_gbp: number, arrangement_fee_gbp: number, total_cost_gbp: number, interest_structure_used: string }. Include in tool metadata so LLMs know what to extract.
• Shorten descriptions to 80-150 chars. E.g., bridging_cost_analyser: 'Calculate total cost of a UK bridging loan under three interest structures (rolled, retained, serviced). Returns APR, interest payable, and arrangement fee.', removes verbose output list, focuses on core action.
• Remove example values from descriptions. Move '2026 bridging rates typically 0.65% to 1.15%' to parameter description, not tool description. Move '{ 'loan_amount_gbp': 500000 }' to schema examples or parameter description, not tool description.
• Add error handling to tool implementations. Validate inputs (e.g., loan_amount_gbp > 0, interest_rate < 50%). Return structured errors: { error: 'invalid_input', code: 'loan_amount_must_be_positive', message: 'Loan amount must be > 0. Got: -50000.', suggestion: 'Try positive values between £10,000 and £10,000,000.' }
• Formalize conditional parameters in development_appraisal. Use schema pattern: either require loan_amount_gbp XOR ltc_pct, never both. Or: if loan_amount_gbp is provided, ltc_pct is ignored (document this clearly).
• Enforce jurisdiction/buyer_type/property_type combinations in uk_stamp_duty_calculator. Consider nested enums: buyer_type values depend on property_type. Or add validation: 'ftb and additional buyer_types only apply to residential; company applies to commercial.'

Inferred effective spec: 2026-07-28+.

• Relies on Stateful initialize / Mcp-Session-Id (removed; protocol is stateless) - make each request self-contained