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Car Rental Brain

by carrentalbrain.com · remote · no sign-in to list tools · v1.0.0 · published by com.carrentalbrain

True cost of car hire at 40+ airports: second driver, cover, deposits, debit cards, desk hours.

Changes · 3
CompareRegistry entry

6 tools: 3 change things and 3 only read.

Scanned Oct 21, 2026

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

claude mcp add --transport http car-rental-brain https://app.carrentalbrain.com/mcp

Findings

Matches of fixed checks, with the text they matched.

1 warn
  • Warnbuild_search_link

    The server marks "build_search_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_search_link" says "search": 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.

6 tools

Changes things 3Claude Code: ask
  • airport_costsThe true cost of hiring a car at one airport: per-day price for the car alone, with a second driver, with full cover, automatic, no-deposit (from + typical); by pick-up month; seco…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
    The true cost of hiring a car at one airport: per-day price for the car alone, with a second driver, with full cover, automatic, no-deposit (from + typical); by pick-up month; second-driver fees; deposits; debit-card acceptance; desk closing times and out-of-hours fees; policies.

    Annotations the server declares

    • title: Airport costs
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • supplier_termsPer supplier at an airport: typical price per day, second-driver fee, full-cover price, deposit held, whether the desk takes a debit card, and customers' desk review scores.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
    Per supplier at an airport: typical price per day, second-driver fee, full-cover price, deposit held, whether the desk takes a debit card, and customers' desk review scores.

    Annotations the server declares

    • title: Supplier terms
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
Only reads 3Claude Code: allow
  • compare_airportsRank airports by real cost (car only / with driver / with cover), typical deposit, debit-card friendliness or late desk hours.No findings

    Why it is in this group

    • The name "compare_airports" says "compare": a word for reading.
    Description, as the server wrote it
    Rank airports by real cost (car only / with driver / with cover), typical deposit, debit-card friendliness or late desk hours. 'Where in Spain is car hire cheapest in March?'

    Annotations the server declares

    • title: Compare airports
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • get_capabilitiesWhat Car Rental Brain measures, how fresh it is, and which airports/countries are covered.No findings

    Why it is in this group

    • The name "get_capabilities" says "get": a word for reading.
    Description, as the server wrote it
    What Car Rental Brain measures, how fresh it is, and which airports/countries are covered.

    Annotations the server declares

    • title: Get capabilities
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • list_airportsAirports we measure, with the typical rental price per day.No findings

    Why it is in this group

    • The name "list_airports" says "list": a word for reading.
    Description, as the server wrote it
    Airports we measure, with the typical rental price per day. Filter by country.

    Annotations the server declares

    • title: List airports
    • 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 1.0.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http car-rental-brain https://app.carrentalbrain.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__car-rental-brain__get_capabilities",
      "mcp__car-rental-brain__list_airports",
      "mcp__car-rental-brain__compare_airports"
    ],
    "ask": [
      "mcp__car-rental-brain__airport_costs",
      "mcp__car-rental-brain__supplier_terms",
      "mcp__car-rental-brain__build_search_link"
    ],
    "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 car-rental-brain. Review it before you use it.