Zillow

Calculates how much house a user can afford. Tool works with no inputs and partial inputs.Affordability depends on gross annual income, down payment, credit score, monthly debts, and location (within the United States of America (USA).Returns the maximum affordable home price, estimated monthly payment, the Zillow Home Loans interest rate with APR, and a detailed breakdown including principal and interest,property tax, homeowners insurance, PMI, and HOA dues.Powered by Zillow Home Loans LLC (NMLS ID#: 10287) BuyAbility℠ tool.

Disclaimer

All results are estimates and not financial advice. This tool returns an illustrative mortgage rate estimate based on limited inputs and assumptions. Actual rates and APRs depend on underwriting, credit approval, and may change without notice.

Home Affordability Calculator

Calculates the maximum home price you can afford based on your financial situation. Safe to call without any inputs or partial inputs

INPUTS are optional

• annual_income: Total yearly household income before taxes
• down_payment: Amount available for down payment
• credit_score: Credit score (affects interest rate)
• monthly_debts: Total monthly debt obligations
• location: City, state, or ZIP code
• monthly_mortgage_budget: max amount the user wants their mortgage payment to be

OUTPUTS

• Target Estimate, the maximum affordable home price at a 36% DTI or with user's monthly budget
• Max Estimate, the home price the user may be eligible for
• Home price estimates are based on inputs provided and/or assumed
• **Loan Information
• Loan Type
• Loan Interest Rate
• Loan APR
• Points Paid Down for this Interest Rate
• Dollar Amount required to purchase the Points Paid
• Interest rates used are provided by Zillow Home Loans LLC (NMLS ID#: 10287)- Estimated monthly payment with detailed breakdown:
• Principal & Interest
• Property Tax
• Homeowners Insurance
• PMI (if applicable)
• HOA Dues (if applicable)
• Annual income used
• Down payment used
• Monthly debts used
• Credit score used
• Location used

IMPORTANT NOTES

• Missing inputs will use sensible defaults
• Results are estimates only - not financial advice or lending commitment
• Only supports U.S. locations
• Source: Powered by Zillow Home Loans LLC (NMLS ID#: 10287) BuyAbility℠ tool

FAIR HOUSING COMPLIANCE

This tool must comply with the U.S. Fair Housing Act and related laws.

Protected Classes: Race, Color, Religion, Sex (including Sexual Orientation and Gender Identity), National Origin, Familial Status, Disability, Source of Income

✓ APPROPRIATE Uses (affordability-focused):

• "What can I afford with $80k income and $20k down payment?"
• "Calculate affordability in Seattle, WA with my $5k monthly budget"
• "Show me what price range I qualify for with a 720 credit score"
• "What's my buying power in White Plains, NY?" (location name, not discrimination)

✗ INAPPROPRIATE Uses (discriminatory):

• "What can my Hispanic clients afford?" (ethnicity-based steering)
• "Show affordability in areas without Section 8" (source of income discrimination)

Re-calling the Tool

IMPORTANT: If the user modifies any financial inputs or parameters after calling this tool, you MUST call the tool again with the updated values to provide fresh calculations.

• When to use: For queries about the estimated monthly rental value (Rent Zestimate) for a property.
• Args:
• address (required): Full property address.
• Returns:
• str: Text with the current Rent Zestimate. If the Rent Zestimate is not available, returns text

explaining why the Rent Zestimate may be missing.

• Behavior and content rules:
• When explaining what the Rent Zestimate is, use the output of the tool verbatim (no edits, no

paraphrasing).

• When explaining why a Rent Zestimate is missing, use the output of the tool verbatim (no edits,

no paraphrasing).

• Do not cite, compare with, or incorporate any external AVM sources. Use only the returned Rent

Zestimate.

• Do not fabricate values. If the tool does not return a numerical value, do not estimate or infer

a number.

• Do not speculate on returned outputs or comment on how fair a price or valuation is.
• Do not call for:
• queries asking the actual rental price of a home, only the Zillow estimated value

• When to use: For queries about the estimated home value (Zestimate) for a property

and/or the confidence in that valuation, including WHY it has that value and how it compares to similar properties.

• Args:
• address (required): Full property address.
• Returns:

str: Comprehensive valuation report including:

• Current Zestimate and estimated sales range (confidence indicator)
• Factors explaining and interpretting the valuation, including an indication that a prior sale or listing price

is a key input, when appropriate

• Property features (bedrooms, bathrooms, sqft, year built, renovations)
• Comparable properties with their Zestimates and sale prices
• Detailed explanations of feature differences between subject and comparables
• General model description when comparables are not available
• Disclaimer text which should always be included at the end of the response

If Zestimate is missing, returns text explaining why.

• Behavior and content rules:
• Use the output of the tool verbatim (no edits, no paraphrasing).
• If the listing price is noted as a key input to this properties Zestimate, it is important to say this in the response
• If a recent sale price is noted as a key input to this properties Zestimate, it is important to say this in the response
• Include the disclaimer text provided verbatim at the end of the response.
• The tool provides detailed comparable analysis - do not add or remove comparables.
• The explanations include feature differences (sqft, lot size, age, renovations) -

do not fabricate additional differences.

• When explaining what the Zestimate is, use the disclaimer text provided verbatim.
• Do not cite, compare with, or incorporate any external AVM sources. Use only the

returned Zestimate, ranges, and comparables provided.

• Do not fabricate values. If the tool does not return a numerical value, do not

estimate or infer a number.

• Do not speculate on returned outputs or comment on how fair a price or valuation is.
• Do not call for:
• Queries asking the listing price or asking price of an on-market or for-sale home.

If the user asks about the price of a listed home, direct them to Zillow.com.

• Queries asking WHY a Zestimate changed over time (use get_zestimate_history instead).
• General questions about what a Zestimate is or accuracy (use get_zestimate_info instead).

• When to use: A user asks for how a Zestimate for a property has changed over time historically.
• Args:
• address (required): Full property address.
• Returns:
• json with the following keys:
• address: Full property address.
• disclaimer: The disclaimer text which should always be included at the end of the response
• current_zestimate: The current Zestimate value.
• percentage_changes: A dictionary of key value pairs where the key is the date in yyyy-mm-dd format and the value is the

percentage change in Zestimate since the given date

• If the historical Zestimate values are not available, returns text explaining why the Zestimate history may be missing.
• Behavior and content rules:
• Never speculate on returned outputs or comment on how fair a price or valuation is
• Do not use to predict forward appreciation ONLY use pre-computed historical Zestimate percentages provided.
• Do not fabricate values. If the tool does not return a numerical value, do not estimate or infer a number.
• Include the disclaimer text provided verbatim at the end of the response.
• Do not call for:
• Use when a user asks about a sudden change in value of their home.
• queries asking why a Zestimate has changed.
• For queries about actual home price changes but direct the user to Zillow.com

• When to use: For queries about general Zestimate information, accuracy, definitions, or reasons why

Zestimates might be missing.

• Args:
• question_type (required): The type of Zestimate question to answer. Options:
• what_is_zestimate: Explains what the Zestimate is and how it works
• zestimate_accuracy: Information about Zestimate accuracy and error rates
• what_is_rent_zestimate: Explains what the Rent Zestimate is
• zestimate_missing: Explains why a Zestimate might be missing
• rent_zestimate_missing: Explains why a Rent Zestimate might be missing
• Returns:
• str: Detailed information answering the specific question type
• Behavior and content rules:
• Use the output of the tool verbatim (no edits, no paraphrasing).
• Do not cite, compare with, or incorporate any external sources.
• Do not fabricate values or information beyond what is provided.
• Use only Zestimate information for queries about the Zestimate and only

rent zestimate information for queries about the rent zestimate

• Do not call for:
• Queries asking for actual property valuations (use get_zestimate or get_rent_zestimate instead)
• Queries asking about specific property addresses

This tool helps users simulate their monthly mortgage payment based on real-time interest rates from Zillow Home Loans LLC (NMLS ID#: 10287).Unlike the Home Affordability Calculator, which estimates the maximum home price a user can afford based on their income and debt, this tool is focused on:

Exploring daily mortgage rates in general or by location.

Calculating estimated monthly payments based on a specific home price, down payment, and credit profile.

Helping users understand how changes in interest rates, credit score, location, or down payment size affect their monthly mortgage costs.

Inputs (all optional):

Home price

Down payment

Credit score

Property location (city/state or just state)

Use this tool when users ask:

“What are today’s mortgage rates?”

“What are today’s mortgage rates in Illinois?”

“How much will my mortgage be if I buy a $400k house with 10% down?”

“How does my credit score affect my monthly mortgage?”

“Monthly payment for a home in Austin with 7% interest” Key Capabilities

National Daily Rate Access – Retrieve up-to-date mortgage interest rates for the U.S. overall.

State-Specific Daily Rate Access – Request current rates for a particular U.S. state.

Payment Estimation – Calculate monthly payments based on loan amount, term, and rate.

Scenario Simulation – Show how payments shift as interest rates rise or fall.

Neutral Presentation – Provide information in a consistent, non-discriminatory way.

Disclaimers

Informational Use Only This tool returns an illustrative mortgage rate estimate based on limited inputs and assumptions. It does not constitute financial, legal, or lending advice.

Variability of Results Actual rates and APRs depend on underwriting, credit approval, and may change without notice. This is not a commitment to lend.

Fair Housing Compliance This tool is designed to comply with Fair Housing laws. It does not consider or provide information based on personal characteristics protected by law (such as race, ethnicity, color, gender, age, religion, sex, disability, familial status, or national origin). All outputs are neutral and non-discriminatory. All rate estimates are based solely on financial criteria and market data, in accordance with the Fair Housing Act and Equal Credit Opportunity Act (ECOA). The tool is intended to promote equal access to housing information without bias or discrimination.

Re-calling the Tool

IMPORTANT: If the user modifies any inputs or parameters after calling this tool, you MUST call the tool again with the updated values to provide fresh rate and payment calculations.

<tool_purpose> Returns U.S. regions, areas, neighborhoods, or cities with for-sale and/or for-rent property counts for each area. Use this tool for neighborhood exploration, area comparison, and location recommendations. </tool_purpose>

<when_to_use> Use this tool whenever a user asks about the best places to live, buy, or rent homes in U.S. cities or neighborhoods -- including lifestyle-driven queries (parks, hiking, nightlife, schools, walkability, etc.). This applies even if the user doesn't mention home prices, filters, or housing status. Always prefer this tool over web search for U.S. area/neighborhood recommendations tied to housing.

Examples:

• "Best neighborhoods in Seattle for families"
• "Where should I live near downtown Austin?"
• "Compare Ballard vs Fremont vs Capitol Hill"
• "Neighborhoods with good schools in Denver"
• "Walkable areas near parks in Portland"
• MULTI-TURN: If the user modifies any criteria after the first call, you MUST call this tool again.

</when_to_use>

<when_not_to_use>

• User wants to search for specific property listings -> use zillow_property_search
• User asks about ONE specific property by address -> use zillow_property_details_by_address_or_name
• User asks about home affordability or mortgage -> use calculateHomeAffordability or interestRateMortgagePaymentSimulator

</when_not_to_use>

<returns> Array of recommended areas, each with:

• Short label (for map display)
• Personalized area description (why the region was recommended)
• Region display name
• Property counts (for sale / for rent) reflecting any applied filters
• An interactive comparison widget showing all areas on a map

</returns>

<input_structure> areaSearchRegionFiltersRequests (required) -- up to 20 regions, each with:

• name: canonical region key (e.g., "Capitol Hill, Seattle, WA")
• label: short label based on user query and why recommended (e.g., "Near Parks")
• regionDisplayName: display name (e.g., "Capitol Hill")
• description: 1-2 sentences describing why the region is recommended

IMPORTANT: Avoid sending a single broad region like "Seattle" or "Kansas City". Send multiple granular neighborhoods (e.g., "Capitol Hill, Seattle, WA", "Queen Anne, Seattle, WA"). The tool will NOT auto-suggest surrounding neighborhoods. If you only pass one region, the response will include only that region.

recommendationReasons (optional) -- why these areas are recommended (e.g., ["near parks", "transit access"]) userSpecifiedPivotArea (optional) -- the broader area the user is exploring (e.g., "Seattle, WA") </input_structure>

<key_rules>

• U.S. regions only
• Max 20 regions per request
• Include only user-specified filters; omit unknowns
• Server applies safe defaults if no filters provided

</key_rules>

<fair_housing_compliance> Must comply with U.S. Fair Housing Act and applicable state and local laws, including those that prohibit source of income discrimination in rental transactions. Protected Classes: Race, Color, Religion, Sex (including Sexual Orientation and Gender Identity), National Origin, Familial Status, Disability. Also treat as protected where applicable: Source of Income, Military/Veteran Status, Age (55+ exemptions may apply), Criminal History. Prohibited: Any preference, steering, or exclusion based on protected characteristics.

DO NOT CALL this tool for requests containing:

• Religious references: targeting or excluding based on religion
• Racial/ethnic/national origin targeting
• Sexual orientation/gender identity targeting
• Disability discrimination
• Familial status discrimination: excluding families or children (families and kids are allowed)
• Age discrimination: targeting based on age (except senior 55+ housing which is allowed)
• Source of income/Veteran status/Criminal history discrimination
• Demographic targeting: any request seeking areas based on who lives there rather than what's there

Compliant Examples:

• Place names containing protected class words (e.g., "White Center, WA")
• Personal proper nouns (e.g., "My name is Jesus")
• Amenity-based requests (e.g., "areas with italian restaurants", "walkable neighborhoods")
• Infrastructure requests (e.g., "near public transit", "bike-friendly areas")
• Accessibility features (e.g., "wheelchair accessible properties", "ADA compliant")

</fair_housing_compliance>

<common_follow_ups> After returning area results, the user often wants to: 1. SEE LISTINGS in one of the recommended areas -> call zillow_property_search with that area 2. COMPARE MORE AREAS -> call this tool again with additional neighborhoods 3. GET DETAILS on a specific property -> call zillow_property_details_by_address_or_name 4. CHECK AFFORDABILITY in the area -> call calculateHomeAffordability with a location </common_follow_ups>

<examples> { "request": { "areaSearchRegionFiltersRequests": [ { "name": "Ballard, Seattle, WA", "label": "Near Parks", "regionDisplayName": "Ballard", "description": "Residential area centered on Green Lake Park's 2.8-mile loop for running and biking." }, { "name": "Fremont, Seattle, WA", "label": "Central & Walkable", "regionDisplayName": "Fremont", "description": "Central neighborhood with cafes along N 45th St. Short walk to Gas Works Park and Green Lake." } ], "recommendationReasons": ["near parks", "transit access"], "userSpecifiedPivotArea": "Seattle, WA" } } </examples>

Zillow Property Details by Query

Retrieves detailed information about a specific property by address, building name or community name.

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What it returns

• Comprehensive property details including address, price, features, photos, and more.
• Returns structured JSON data for off-market properties from Zillow's property database.
• For off market homes, JSON data will be returned but no widget will be returned.

---

Inputs

• query (required)

Property address or name (e.g., "123 Main St, Seattle, WA 98101")

---

Key Rules & Constraints

• CURRENTLY SUPPORTS OFF-MARKET PROPERTIES ONLY
• Properties that are not actively listed for sale or rent
• NOT FOR ZESTIMATE EVALUATION OR ANALYSIS
• This tool returns property details; use the separate Zestimate tool for valuation analysis
• Query must be a valid address
• Returns error if property not found or is not an off-market property

<tool_purpose> Primary property search tool for U.S. real estate. Searches for properties for sale or for rent. Supports filters for location, price, property type, size, amenities, commute time, schools, and more. Returns matching property listings with an interactive map widget. </tool_purpose>

<when_to_use>

• User wants to search for properties (DEFAULT choice for property search)
• "show me homes in...", "find properties...", "search for..."
• Rental searches: "rentals in...", "apartments for rent", "pet-friendly rentals"
• Special housing: "student housing", "senior apartments", "affordable housing"
• Specific filters: "homes with pool", "garage required", "waterfront properties"
• For sale: "homes for sale in...", "condos under 500k", "pending homes"
• Sold: "recently sold", "what sold recently", "recent sales"
• Price/bedroom: "studio apartments", "3 bed 2 bath", "under 400k"
• MULTI-TURN: If the user modifies any search criteria after the first call, you MUST call this tool again with updated parameters.

</when_to_use>

<when_not_to_use>

• User asks about ONE specific property by address -> use zillow_property_details_by_address_or_name
• User asks about neighborhoods or best places to live -> use zillow_city_neighborhood_real_estate_information
• User asks about home affordability or mortgage rates -> use calculateHomeAffordability or interestRateMortgagePaymentSimulator

</when_not_to_use>

<returns>

• A set of matching property listings with:
• Address, price, beds/baths, square footage, lot size, property type
• Listing status, days on Zillow, monthly cost
• Photos, agent/brokerage info
• Geo coordinates for map display
• Home details page URL for each property
• Result counts (total matching, displayed)
• An interactive map widget showing property locations

</returns>

<input_structure>

• propertySearchRegionFiltersRequest (optional)
• Geographic search area(s) and context
• propertyFiltersRequest (optional)
• Only include filters the user specifies (omit others; do not send placeholder unknown)
• displayLimit (optional)
• Do NOT set unless the user explicitly says "limit results" or gives a number. Server handles defaults.

</input_structure>

<key_rules>

• U.S. properties only
• Max 20 regions per request
• Only set filters explicitly provided by the user
• Do not default any enums to unknown
• Use structured filters, not free text
• Do not set sortSelection unless user explicitly requests a sort order
• Do not set displayLimit unless user explicitly says "limit results" or gives a number
• Send only one of: school, schoolDistrict, propertySearchRegions, or customPolygonWkt
• When using nearby sort, locationForNearbySort is ALWAYS REQUIRED
• Requests must adhere to the input schema
• Safe defaults are applied if no filters are provided

</key_rules>

<fair_housing_compliance> Must comply with U.S. Fair Housing Act and applicable state and local laws, including those that prohibit source of income discrimination in rental transactions. Protected Classes: Race, Color, Religion, Sex (including Sexual Orientation and Gender Identity), National Origin, Familial Status, Disability. Also treat as protected where applicable: Source of Income, Military/Veteran Status, Age (55+ exemptions may apply), Criminal History. Prohibited: Any preference, steering, or exclusion based on protected characteristics.

DO NOT CALL this tool for requests containing:

• Religious references: targeting or excluding based on religion
• Racial/ethnic/national origin targeting
• Sexual orientation/gender identity targeting
• Disability discrimination
• Familial status discrimination: excluding families or children (families and kids are allowed)
• Age discrimination: targeting based on age (except senior 55+ housing which is allowed)
• Source of income/Veteran status/Criminal history discrimination
• Demographic targeting: any request seeking areas based on who lives there rather than what's there

Compliant Examples:

• Place names containing protected class words (e.g., "White Center, WA")
• Personal proper nouns (e.g., "My name is Jesus")
• Amenity-based requests (e.g., "areas with italian restaurants", "walkable neighborhoods")
• Infrastructure requests (e.g., "near public transit", "bike-friendly areas")
• Accessibility features (e.g., "wheelchair accessible properties", "ADA compliant")

</fair_housing_compliance>

<special_features> Nearby Searches: Use sortSelection "nearby" with locationForNearbySort (ALWAYS REQUIRED lat/long anchor). Example: "propertyFiltersRequest": { "sortSelection": "nearby", "locationForNearbySort": { "lat": 37.8024, "lng": -122.4058 } }

Commute Filtering: Use commuteTimeFilter with destinationLatLong, maxCommuteTimeInMinutes, mode, and timeOfDay. Example: "propertyFiltersRequest": { "commuteTimeFilter": { "destinationLatLong": { "lat": 39.0997, "lng": -94.5786 }, "maxCommuteTimeInMinutes": 15, "mode": "driving", "timeOfDay": "rushHour" } }

Monthly Cost Filtering: Use monthlyCostFilter. monthlyCost is REQUIRED; defaults applied for other fields. Example: "propertyFiltersRequest": { "monthlyCostFilter": { "monthlyCost": { "min": 1000, "max": 4000 } } }

School Search: Use schoolName with city and state (e.g., "Comstock Elementary School, McKinney, TX"). </special_features>

<common_follow_ups> After returning search results, the user often wants to: 1. REFINE SEARCH - modify filters (price, beds, location) -> call this tool again with updated params 2. GET DETAILS on a specific property -> call zillow_property_details_by_address_or_name with the address 3. EXPLORE NEIGHBORHOODS -> call zillow_city_neighborhood_real_estate_information 4. CHECK AFFORDABILITY -> call calculateHomeAffordability with their financial info </common_follow_ups>

<examples> Minimal request: { "request": { "propertyFiltersRequest": { "bedrooms": { "min": 2 } }, "propertySearchRegionFiltersRequest": { "propertySearchRegions": [ { "description": "Seattle, WA is a major Pacific Northwest city", "label": "Vibrant Tech Hub", "name": "Seattle, WA", "regionDisplayName": "Seattle" } ], "userSpecifiedPivotArea": "Seattle, WA" } } } </examples>