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com.smartmoney77/financial-calculators

by smartmoney77.com · remote · no sign-in to list tools · v0.6.0 · published by com.smartmoney77

Financial calculators over MCP: compound interest, FIRE, historical returns, deep links, 6 languages

Changes · 10
CompareRegistry entry

14 tools: 10 change things and 4 only read.

Scanned Oct 21, 2026

2 checks matched something in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http financial-calculators https://smartmoney77.com/mcp

Findings

Matches of fixed checks, with the text they matched.

2 warn
  • Warnbuild_calculator_link

    The server marks "build_calculator_link" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

    Matched text

    annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The name "build_calculator_link" says "link": a word for a change.

    What this check looks for
  • Warncompare_investments

    The server marks "compare_investments" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

    Matched text

    annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":true}; The name "compare_investments" says "compare": a word for reading.

    What this check looks for

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

14 tools

Changes things 10Claude Code: ask
  • build_share_packBuild everything needed to share a SmartMoney77 calculation on social media in one call: the deep link to the result, a ready-to-embed 1200x628 image URL rendered on our servers, a…No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Build everything needed to share a SmartMoney77 calculation on social media in one call: the deep link to the result, a ready-to-embed 1200x628 image URL rendered on our servers, a link that opens the on-site share modal (1200x628, 1080x1080, 1080x1920 downloads), and a localized caption with attribution. Works for all 31 calculators. Example: { "calculator": "fire-number", "lang": "en", "params": { "expenses": 4000, "saving": 1500 } }

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • compare_investmentsRun the same "what if I had invested" calculation across 2-8 assets and rank them by final value.1 finding

    Why it is in this group

    • The name "compare_investments" says "compare": a word for reading.
    • The description's first verb is "run": a word for a change.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

    Findings

    • Warn

      The server marks "compare_investments" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

      Matched text

      annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":true}; The name "compare_investments" says "compare": a word for reading.

      What this check looks for
    Description, as the server wrote it
    Run the same "what if I had invested" calculation across 2-8 assets and rank them by final value. USD only, same yearly low/high average pricing as the SmartMoney77 history calculators. Assets: bitcoin, ethereum, solana, sp500, nasdaq100, nvidia, microsoft, meta, apple, tesla, amazon, google, netflix, amd, gold, silver, oil. Example: { "amount": 1000, "buy_year": 2015, "assets": ["bitcoin", "sp500", "gold"] } → each asset's value today, sorted best first, each with its own reproduction link.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • compound_interestProject the future value of an initial amount plus monthly contributions at a given annual return (monthly compounding), and return a link to the same calculation on SmartMoney77.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Project the future value of an initial amount plus monthly contributions at a given annual return (monthly compounding), and return a link to the same calculation on SmartMoney77. Example: { "initial": 10000, "monthly": 500, "rate": 8, "years": 20 } → futureValue = 343,778. Monthly contributions are made at the end of each month (ordinary annuity).

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • credit_card_payoffCalculate how long it takes to clear a credit card balance at a fixed monthly payment and APR, plus the total interest paid.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Calculate how long it takes to clear a credit card balance at a fixed monthly payment and APR, plus the total interest paid. Example: { "balance": 10000, "payment": 400, "rate": 18 } → about 32 months and ~2,600 in interest. Errors when the payment is smaller than the first month's interest.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • emergency_fundCalculate how many months of expenses current savings cover, the target emergency fund size, the gap, and how long it takes to close it.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Calculate how many months of expenses current savings cover, the target emergency fund size, the gap, and how long it takes to close it. Example: { "expenses": 3000, "savings": 6000, "contribution": 500, "target": 6 } → 2 months covered, target 18,000, gap 12,000, 24 months to go.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • fire_numberCalculate the financial-independence (FIRE) target from monthly expenses using the 4% rule, plus how many years of saving are needed.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Calculate the financial-independence (FIRE) target from monthly expenses using the 4% rule, plus how many years of saving are needed. Example: { "expenses": 4000, "saving": 1500, "current": 50000 } → fireNumber 1,200,000.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • historical_investment_returnCompute what a past investment would be worth today (or in a later year), using the same yearly low/high average prices as the SmartMoney77 history calculators.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Compute what a past investment would be worth today (or in a later year), using the same yearly low/high average prices as the SmartMoney77 history calculators. All amounts and prices are in USD only. Assets: bitcoin, ethereum, solana, sp500, nasdaq100, nvidia, microsoft, meta, apple, tesla, amazon, google, netflix, amd, gold, silver, oil. Example: { "asset": "bitcoin", "amount": 1000, "buy_year": 2015 } → units bought, current value, profit, total return and CAGR, plus a link that reproduces it on the site.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • inflation_checkCalculate how much purchasing power cash loses to inflation over time, and what nominal amount keeps the same buying power.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Calculate how much purchasing power cash loses to inflation over time, and what nominal amount keeps the same buying power. Example: { "amount": 100000, "rate": 3, "years": 10 } → realValue ≈ 74,409 and equivalentNeeded ≈ 134,392.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • latte_factorCalculate what a small recurring daily expense (coffee, cigarettes, takeaway) costs over time and what it would grow to if invested instead.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Calculate what a small recurring daily expense (coffee, cigarettes, takeaway) costs over time and what it would grow to if invested instead. Monthly cost = cost × perWeek × 52 / 12, and monthly contributions are made at the end of each month (ordinary annuity). Example: { "cost": 5, "years": 30, "rate": 8, "perWeek": 5 } → ~108/month spent and a six-figure invested balance.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
Only reads 4Claude Code: allow
  • cost_of_waitingCompare investing the same monthly amount starting at an early age versus a later age, and show what the delay costs by retirement.No findings

    Why it is in this group

    • The description's first verb is "compare": a word for reading.
    Description, as the server wrote it
    Compare investing the same monthly amount starting at an early age versus a later age, and show what the delay costs by retirement. Example: { "monthly": 1000, "start": 25, "compare": 35, "retire": 67, "rate": 8 } → a large gap created mostly by compounding, not by the extra contributions.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • get_tool_guideDiscovery helper: returns the standard prompt template, argument template, output-interpretation guide and related resources for one or all SmartMoney77 tools, so you can call them…No findings

    Why it is in this group

    • The name "get_tool_guide" says "get": a word for reading.
    Description, as the server wrote it
    Discovery helper: returns the standard prompt template, argument template, output-interpretation guide and related resources for one or all SmartMoney77 tools, so you can call them correctly without guessing. Example: { "tool": "fire_number" }.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • killer_feesCompare how much a high management fee costs versus a low fee over time on a portfolio with monthly contributions.No findings

    Why it is in this group

    • The description's first verb is "compare": a word for reading.
    Description, as the server wrote it
    Compare how much a high management fee costs versus a low fee over time on a portfolio with monthly contributions. Example: { "portfolio": 100000, "monthly": 1000, "highFee": 1.5, "lowFee": 0.3, "years": 25 } → the low-fee portfolio ends materially higher.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • list_calculatorsList every SmartMoney77 calculator with its slug, accepted URL parameters and supported languages/currencies.No findings

    Why it is in this group

    • The name "list_calculators" says "list": a word for reading.
    Description, as the server wrote it
    List every SmartMoney77 calculator with its slug, accepted URL parameters and supported languages/currencies. Call this before build_calculator_link. Example: { "group": "history" } returns only the 'what if I had invested' tools.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 0.6.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http financial-calculators https://smartmoney77.com/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json
{
  "permissions": {
    "allow": [
      "mcp__financial-calculators__get_tool_guide",
      "mcp__financial-calculators__list_calculators",
      "mcp__financial-calculators__killer_fees",
      "mcp__financial-calculators__cost_of_waiting"
    ],
    "ask": [
      "mcp__financial-calculators__build_calculator_link",
      "mcp__financial-calculators__build_share_pack",
      "mcp__financial-calculators__compound_interest",
      "mcp__financial-calculators__fire_number",
      "mcp__financial-calculators__credit_card_payoff",
      "mcp__financial-calculators__emergency_fund",
      "mcp__financial-calculators__inflation_check",
      "mcp__financial-calculators__latte_factor",
      "mcp__financial-calculators__historical_investment_return",
      "mcp__financial-calculators__compare_investments"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as financial-calculators. Review it before you use it.