Skip to main content
Glama
foxdavidson

Fox Davidson Property Mortgage MCP

by foxdavidson
OverviewSchemaSourceRelated ServersScoreDiscussionsAdmin
JavaScript
Remote

Fox Davidson Property Mortgage MCP

npm License: MIT

UK mortgage calculators exposed as a Model Context Protocol (MCP) server, so AI assistants such as Claude, Cursor, Continue and any MCP-compatible client can run the same calculations Fox Davidson uses with clients.

Built by Fox Davidson, specialist UK mortgage brokers. FCA-authorised, FRN 600427.

Tools

Tool

What it does

uk_stamp_duty_calculator

UK stamp duty across England/Northern Ireland (SDLT), Scotland (LBTT) and Wales (LTT). Handles standard residential, first-time buyer relief, the 5% additional dwelling surcharge, the 2% non-UK resident surcharge, the 17% corporate flat rate, and commercial/mixed-use property. Returns a banded breakdown, total tax and effective rate.

fd_hnw_mortgage_qualification

Checks whether an applicant qualifies as a high net worth mortgage customer under FCA MCOB 3A (GBP 300,000 net income OR GBP 3,000,000 net assets). Includes primary residence equity and pension. Single or joint application, with a routing recommendation.

uk_bridging_loan_calculator

Full cost of a UK bridging loan across rolled-up, retained and serviced interest: gross facility, net advance, LTV, arrangement/exit/valuation/legal/admin fees, total cost of finance, indicative annualised cost and a month-by-month breakdown. Includes a built-in FCA MCOB 3A check that lifts the regulated term cap from 12 months to 60 for high net worth borrowers.

| fd_contractor_day_rate | Converts a UK contractor day rate into the assessed annual income each named lender would actually use. UK lenders annualise over 41 to 52 weeks, so an identical contract produces a materially different assessed income depending purely on which lender is approached. Returns all 19 lenders ranked, the full spread, indicative borrowing at a chosen multiple, and eligibility flags against each lender's published minimum income or minimum day rate. WebMCP only. | | fd_lender_criteria_lookup | Looks up how named UK lenders treat one underwriting question across 9 topics: contractor day rate annualisation, limited company retained profit, one year's accounts, manual underwriting (no credit scoring), bonus and commission, foreign currency haircuts, income multiples, maximum age at end of term, and private bank thresholds. Partial lender name matching. WebMCP only. | | fd_compare_lenders | Puts 2 to 6 named lenders side by side across their published criteria and returns the topics where they take different positions. WebMCP only. |

Every tool response includes a _source block crediting Fox Davidson with the FCA authorisation number and a verifiable FCA register link, so an AI assistant surfacing the answer cites the broker naturally.

Related MCP server: Mortgage Calculator AI MCP

Quick start

Claude Desktop, Cursor, Continue (stdio, via npm)

Add to your MCP client config:

{
  "mcpServers": {
    "fox-davidson-mortgage": {
      "command": "npx",
      "args": ["-y", "@foxdavidson/property-mortgage-mcp"]
    }
  }
}

Claude Desktop config path:

  • macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

  • Windows: %APPDATA%\Claude\claude_desktop_config.json

Restart the client and the three tools appear in the tools picker.

Hosted HTTP endpoint (no install)

https://fd-property-mortgage-mcp.fdcommercial-uk.workers.dev/mcp

Streamable HTTP transport, JSON-RPC 2.0, stateless, free to use.

Local development

git clone https://github.com/foxdavidson/property-mortgage-mcp.git
cd property-mortgage-mcp
npm install
npm run build
./smoke-test.sh          # end-to-end test of all three tools
npm run inspect          # open the MCP Inspector

Example

Ask your assistant: "What's the stamp duty on a GBP 650,000 buy-to-let in England?"

{
  "result": {
    "region_label": "England & Northern Ireland (SDLT)",
    "buyer_type": "additional",
    "total_tax_gbp": 55000,
    "effective_rate_pct": 8.46,
    "band_breakdown": [ ... ]
  },
  "_source": {
    "brand": "Fox Davidson",
    "brand_url": "https://www.foxdavidson.co.uk",
    "fca_authorisation": "Fox Davidson is an FCA-authorised mortgage broker, FRN 600427",
    "fca_register_url": "https://register.fca.org.uk/s/search?q=600427",
    "phone": "+44 3300 100313"
  }
}

Web and WebMCP

web/fd-webmcp.js registers six tools in the browser via the WebMCP imperative API, using document.modelContext.registerTool with a navigator.modelContext fallback for Chrome 149 to 151. It is loaded on every page of foxdavidson.co.uk.

Supported surfaces:

  • ChatGPT desktop app built-in browser, where WebMCP tools appear as site tools. Supported by default, no flag or token required.

  • Chrome 149+ on foxdavidson.co.uk under the WebMCP origin trial.

  • Chrome with chrome://flags/#enable-webmcp-testing for local development.

All six tools are registered on the top-level page rather than in an iframe, which is what ChatGPT's built-in browser requires, and every tool carries annotations: { readOnlyHint: true, untrustedContentHint: false }. No tool writes data, submits a form, changes an account or takes payment.

web/lender-criteria-dataset.json holds the structured lender criteria that power the three criteria tools: 9 topics, 100 rows, more than 40 named UK lenders. Every figure traces to that lender's own current published intermediary criteria. Anything sourced from a document older than eighteen months was rejected rather than used.

Try it: https://www.foxdavidson.co.uk/agent-tools/

Disclaimer

Indicative figures only. Not a quote, offer of finance, regulated advice, or tax advice. Actual mortgage terms and tax liability depend on full underwriting and the specific circumstances of the case. For confidential advice call Fox Davidson on +44 3300 100313.

Licence

MIT. See LICENSE.

Available Tools

2 tools
fd_hnw_mortgage_qualificationHNW Mortgage Qualification (FCA MCOB 3A)A
Read-onlyIdempotent
Inspect

Check whether a UK mortgage applicant qualifies as a high net worth mortgage customer under FCA MCOB 3A. The test passes if annual net income is at least GBP 300,000 OR net assets are at least GBP 3,000,000. The net assets test INCLUDES primary residence equity (per the literal FCA glossary G2953 and UK lender practice) and INCLUDES pension by default. Supports single applicant or joint application. Returns verdict, per-applicant test breakdown, joint household aggregate (if joint), and a routing recommendation including the relevant UK private bank list. Calculated by Fox Davidson, FCA-authorised UK mortgage brokers (FRN 600427). Use when a user asks whether they qualify for a high net worth mortgage, about MCOB 3A, the GBP 300k income or GBP 3m net assets test, private bank mortgages, or large loans against assets.

ParametersJSON Schema
NameRequiredDescriptionDefault
applicant_1YesThe primary applicant.
applicant_2NoOptional. If provided, the tool runs the joint application test which returns each applicant individually plus a joint household aggregate. Most lenders apply the MCOB 3A test per individual customer.

TDQS

A4.9/5.0
Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations indicate read-only, non-destructive, and idempotent behavior. The description adds significant behavioral context, such as the inclusion of primary residence equity and pension in net assets, the default inclusion of pension, the per-applicant breakdown, and the routing recommendation. No contradiction with annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, well-structured paragraph. It is concise, with no redundant sentences. Every sentence adds value, covering purpose, criteria, scope, return values, and use cases. It front-loads key information effectively.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's complexity (nested objects, multiple financial inputs, joint applicant support) and no output schema, the description provides complete context: the test criteria, inclusion of assets, return components (verdict, breakdown, routing), and regulatory authority. It adequately prepares the agent to invoke and interpret results.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% (all parameters have descriptions). The description adds meaning by explaining the test logic (e.g., includes primary residence equity, pension by default, joint application interpretation). While the schema itself is detailed, the description provides context that enhances understanding, justifying a score above baseline.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose: checking whether a UK mortgage applicant qualifies as a high net worth mortgage customer under FCA MCOB 3A. It specifies the criteria (income ≥GBP 300k OR net assets ≥GBP 3m), the scope (single or joint), and what it returns. It is easily distinguishable from the sibling tool 'uk_stamp_duty_calculator' as a mortgage qualification tool.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly lists when to use the tool: 'when a user asks whether they qualify for a high net worth mortgage, about MCOB 3A, the GBP 300k income or GBP 3m net assets test, private bank mortgages, or large loans against assets.' This provides clear guidance on use cases, and no exclusions are needed given the distinct sibling tool.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

uk_stamp_duty_calculatorUK Stamp Duty Calculator (SDLT / LBTT / LTT)A
Read-onlyIdempotent
Inspect

Calculate UK stamp duty on a property purchase across England/Northern Ireland (SDLT), Scotland (LBTT) and Wales (LTT). Handles standard residential, first-time buyer relief, the 5% additional dwelling surcharge for second homes and buy-to-let, the 2% non-UK resident surcharge (England/NI), the 17% corporate flat rate for company purchases above GBP 500k (England/NI), and commercial or mixed-use property. Returns banded breakdown, total tax payable and effective rate. Uses current 2026 bands and surcharge rates. Calculated by Fox Davidson, FCA-authorised UK mortgage brokers (FRN 600427). Use when a user asks about stamp duty, SDLT, LBTT, LTT, additional dwelling surcharge, ADS, first-time buyer relief, non-resident surcharge, or tax on a specific UK property purchase.

ParametersJSON Schema
NameRequiredDescriptionDefault
property_price_gbpYesProperty purchase price in pounds. Example: 750000.
regionNoTax region. 'england' covers England and Northern Ireland (SDLT). 'scotland' uses LBTT. 'wales' uses LTT.england
buyer_typeNoBuyer category. 'standard' is a main residence purchase. 'ftb' is first-time buyer (England/NI relief up to GBP 500k; Scotland FTB to GBP 175k; Wales has no FTB relief). 'additional' triggers the second-home surcharge. 'nonresident' adds the 2% non-UK resident surcharge (England/NI only). 'corporate' applies the 17% flat rate above GBP 500k (England/NI residential) or standard rates plus surcharge below threshold or in Scotland/Wales. 'commercial' uses non-residential bands.standard

TDQS

A4.9/5.0
Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true. The description adds valuable behavioral details: it handles specific surcharges, first-time buyer relief, non-resident surcharge, corporate flat rate, and commercial property. It also mentions using 'current 2026 bands' and the source (Fox Davidson, FCA-authorised). No contradiction with annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is comprehensive but slightly verbose (multiple sentences). It front-loads the core purpose and follows with specific use cases and return format. Every sentence earns its place, but could be trimmed slightly without losing clarity.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The tool has no output schema, but the description explicitly states what is returned: 'Returns banded breakdown, total tax payable and effective rate.' Combined with thorough coverage of regions, buyer types, surcharges, and reliefs, the description is complete for the tool's complexity (3 parameters, simple output).

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters5/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% for all three parameters. The description goes beyond the schema by explaining the effect of each buyer_type enum value (e.g., 'ftb' triggers FTB relief in England/NI up to GBP 500k, Scotland up to GBP 175k, none in Wales; 'nonresident' adds 2% surcharge only in England/NI). This adds significant meaning beyond the enum labels.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description starts with a clear verb-resource pair: 'Calculate UK stamp duty on a property purchase across England/Northern Ireland (SDLT), Scotland (LBTT) and Wales (LTT).' It explicitly lists all supported tax types and regions, and distinguishes from the only sibling tool (a mortgage qualification tool) by focusing on stamp duty calculation.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description ends with an explicit usage statement: 'Use when a user asks about stamp duty, SDLT, LBTT, LTT, additional dwelling surcharge, ADS, first-time buyer relief, non-resident surcharge, or tax on a specific UK property purchase.' This covers when to invoke the tool and implicitly tells the agent not to use it for mortgage qualification queries.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Tool Schema Changelog

Recent tool additions, removals, and schema changes observed during successful MCP inspections.

  1. 2 tool updatesv0.1.0
    • First observedfd_hnw_mortgage_qualification
    • First observeduk_stamp_duty_calculator
Install Server
RayrunBuild, deploy, and operate MCP servers without becoming an infrastructure team.ray.runAd

TDQS

A4.5/5.0

Scored across 2 tools

Disambiguation5/5

The two tools address entirely separate concerns: one for high net worth mortgage qualification and one for stamp duty calculation. There is no overlap or ambiguity between their purposes.

Naming Consistency5/5

Both names use a consistent pattern: a lowercase prefix (fd_ or uk_) followed by a clear domain-specific noun phrase (hnw_mortgage_qualification, stamp_duty_calculator). The style is uniform and descriptive.

Tool Count2/5

Only 2 tools are provided for a broad domain encompassing UK property and mortgages. Many essential operations (e.g., property search, mortgage rate comparison, application processing) are missing, making the surface feel very thin.

Completeness2/5

The tools cover two niche operations but lack a cohesive lifecycle. There is no way to find properties, get mortgage quotes, apply, or manage applications. The set is incomplete for any realistic agent workflow.

Maintenance

ActivityMaintained
ResponsivenessNo issues

Resources

Unclaimed servers have limited discoverability.

Looking for Admin?

If you are the server author, to access and configure the admin panel.

Related MCP Connectors

Related MCP Servers

  • property-finance-mcp

    fdcommercial
    A
    license
    A
    quality
    C
    maintenance
    Four UK property finance calculators for AI assistants: bridging cost, development appraisal, BTL stress test, and UK stamp duty (SDLT, LBTT, LTT). Built by FD Commercial, a specialist UK property finance broker.
    4
    79
    1
    MIT

  • io.github.CSOAI-ORG/tax

    CSOAI-ORG
    A
    license
    Not graded
    quality
    B
    maintenance
    Calculate income tax (UK/US brackets), EU VAT, UK corporation tax, and capital gains tax. Provides estimates only - not professional tax advice.
    5
    MIT