diff --git a/app/actions.tsx b/app/actions.tsx
index 167d23d4..4cd8b38b 100644
--- a/app/actions.tsx
+++ b/app/actions.tsx
@@ -30,7 +30,7 @@ import { MapQueryHandler } from '@/components/map/map-query-handler'
 
 // Define the type for related queries
 type RelatedQueries = {
-  items: { query: string }[]
+  items: string[]
 }
 
 async function submit(formData?: FormData, skip?: boolean) {
diff --git a/components/search-related-optimized.tsx b/components/search-related-optimized.tsx
index b2e1c701..3ee2900b 100644
--- a/components/search-related-optimized.tsx
+++ b/components/search-related-optimized.tsx
@@ -50,8 +50,8 @@ export const SearchRelated: React.FC<SearchRelatedProps> = React.memo(({
   // OPTIMIZATION: Memoize filtered and mapped items
   const relatedItems = useMemo(() => {
     return data?.items
-      ?.filter(item => item?.query !== '')
-      .map((item, index) => (
+      ?.filter(query => query !== '')
+      .map((query, index) => (
         <div 
           key={`related-${index}`}
           className="flex items-start w-full animate-in fade-in slide-in-from-bottom-2 duration-300"
@@ -60,9 +60,9 @@ export const SearchRelated: React.FC<SearchRelatedProps> = React.memo(({
           <Button
             variant="link"
             className="flex-1 justify-start px-0 py-1 h-fit font-semibold text-accent-foreground/50 whitespace-normal text-left"
-            onClick={() => handleRelatedClick(item?.query || '')}
+            onClick={() => handleRelatedClick(query || '')}
           >
-            {item?.query}
+            {query}
           </Button>
         </div>
       )) || []
diff --git a/components/search-related.tsx b/components/search-related.tsx
index b2e1c701..3ee2900b 100644
--- a/components/search-related.tsx
+++ b/components/search-related.tsx
@@ -50,8 +50,8 @@ export const SearchRelated: React.FC<SearchRelatedProps> = React.memo(({
   // OPTIMIZATION: Memoize filtered and mapped items
   const relatedItems = useMemo(() => {
     return data?.items
-      ?.filter(item => item?.query !== '')
-      .map((item, index) => (
+      ?.filter(query => query !== '')
+      .map((query, index) => (
         <div 
           key={`related-${index}`}
           className="flex items-start w-full animate-in fade-in slide-in-from-bottom-2 duration-300"
@@ -60,9 +60,9 @@ export const SearchRelated: React.FC<SearchRelatedProps> = React.memo(({
           <Button
             variant="link"
             className="flex-1 justify-start px-0 py-1 h-fit font-semibold text-accent-foreground/50 whitespace-normal text-left"
-            onClick={() => handleRelatedClick(item?.query || '')}
+            onClick={() => handleRelatedClick(query || '')}
           >
-            {item?.query}
+            {query}
           </Button>
         </div>
       )) || []
diff --git a/components/suggestions-dropdown.tsx b/components/suggestions-dropdown.tsx
index 33be6e48..99f23921 100644
--- a/components/suggestions-dropdown.tsx
+++ b/components/suggestions-dropdown.tsx
@@ -23,7 +23,7 @@ export const SuggestionsDropdown: React.FC<SuggestionsDropdownProps> = ({
   const dropdownRef = useRef<HTMLDivElement>(null)
 
   const suggestionItems = useMemo(
-    () => suggestions?.items?.filter(item => item?.query) || [],
+    () => (suggestions?.items?.filter(query => query) as string[]) || [],
     [suggestions]
   )
 
@@ -47,7 +47,7 @@ export const SuggestionsDropdown: React.FC<SuggestionsDropdownProps> = ({
       } else if (e.key === 'Enter') {
         e.preventDefault()
         if (selectedIndex >= 0 && suggestionItems[selectedIndex]) {
-          onSelect(suggestionItems[selectedIndex].query!)
+          onSelect(suggestionItems[selectedIndex])
         }
       } else if (e.key === 'Escape') {
         onClose()
@@ -92,8 +92,8 @@ export const SuggestionsDropdown: React.FC<SuggestionsDropdownProps> = ({
     >
       <div className="p-2">
         <p className="text-sm text-muted-foreground px-2 pb-1">Suggestions</p>
-        {suggestionItems.map((item, index) => {
-          if (!item?.query) return null
+        {suggestionItems.map((query, index) => {
+          if (!query) return null
           return (
             <Button
               key={index}
@@ -102,11 +102,11 @@ export const SuggestionsDropdown: React.FC<SuggestionsDropdownProps> = ({
                 'w-full justify-start px-2 py-1 h-fit font-normal text-accent-foreground whitespace-normal text-left',
                 selectedIndex === index && 'bg-accent'
               )}
-              onClick={() => onSelect(item.query!)}
+              onClick={() => onSelect(query)}
               onMouseEnter={() => setSelectedIndex(index)}
             >
               <ArrowRight className="h-4 w-4 mr-2 flex-shrink-0" />
-              {item.query}
+              {query}
             </Button>
           )
         })}
diff --git a/lib/agents/query-suggestor.tsx b/lib/agents/query-suggestor.tsx
index 7cb8e50c..f7cd53eb 100644
--- a/lib/agents/query-suggestor.tsx
+++ b/lib/agents/query-suggestor.tsx
@@ -57,7 +57,7 @@ export async function querySuggestor(
   // OPTIMIZATION: Use a more concise system prompt to reduce token usage
   const result = await streamObject({
     model: (await getModel()) as LanguageModel,
-    system: `Generate 3 follow-up queries that explore the subject matter deeper. Format as JSON with an "items" array containing objects with "query" fields. Keep queries concise and relevant.`,
+    system: `Generate 3 follow-up queries that explore the subject matter deeper. Format as JSON with an "items" array containing strings. Keep queries concise and relevant.`,
     messages,
     schema: relatedSchema,
     temperature: 0.7, // Lower temperature for more consistent results
diff --git a/lib/agents/tools/geospatial.tsx b/lib/agents/tools/geospatial.tsx
index 863f59b5..769ca098 100644
--- a/lib/agents/tools/geospatial.tsx
+++ b/lib/agents/tools/geospatial.tsx
@@ -241,7 +241,7 @@ Uses the Mapbox Search Box Text Search API endpoint to power searching for and g
 ,
   parameters: geospatialQuerySchema,
   execute: async (params: z.infer<typeof geospatialQuerySchema>) => {
-    const { queryType, includeMap = true } = params;
+    const { queryType, includeMap = true, latitude, longitude } = params;
     console.log('[GeospatialTool] Execute called with:', params, 'and map provider:', mapProvider);
 
     const uiFeedbackStream = createStreamableValue<string>();
@@ -275,19 +275,19 @@ Uses the Mapbox Search Box Text Search API endpoint to power searching for and g
           // as I don't have a way to inspect it at the moment.
           const place = (gsr as any).results[0].place;
           if (place) {
-            const { latitude, longitude } = place.coordinates;
+            const { latitude: lat, longitude: lng } = place.coordinates;
             const place_name = place.displayName;
 
             const mcpData: McpResponse = {
               location: {
-                latitude,
-                longitude,
+                latitude: lat,
+                longitude: lng,
                 place_name,
               },
             };
 
             if (mapProvider === 'google') {
-              mcpData.mapUrl = getGoogleStaticMapUrl(latitude, longitude);
+              mcpData.mapUrl = getGoogleStaticMapUrl(lat, lng);
             }
 
             feedbackMessage = `Found location: ${place_name}`;
@@ -355,12 +355,18 @@ Uses the Mapbox Search Box Text Search API endpoint to power searching for and g
             return { places: [params.origin, params.destination], includeMapPreview: includeMap, mode: params.mode || 'driving' };
           }
           case 'reverse': { 
-            if (!params.coordinates) throw new Error("'reverse' query requires coordinates");
-            return { searchText: `${params.coordinates.latitude},${params.coordinates.longitude}`, includeMapPreview: includeMap, maxResults: params.maxResults || 5 };
+            if (latitude === undefined || longitude === undefined) throw new Error("'reverse' query requires latitude and longitude");
+            return { searchText: `${latitude},${longitude}`, includeMapPreview: includeMap, maxResults: params.maxResults || 5 };
           }
           case 'search': {
             if (!params.query) throw new Error("'search' query requires query");
-            return { searchText: params.query, includeMapPreview: includeMap, maxResults: params.maxResults || 5, ...(params.coordinates && { proximity: `${params.coordinates.latitude},${params.coordinates.longitude}` }), ...(params.radius && { radius: params.radius }) };
+            return {
+              searchText: params.query,
+              includeMapPreview: includeMap,
+              maxResults: params.maxResults || 5,
+              ...(latitude !== undefined && longitude !== undefined && { proximity: `${latitude},${longitude}` }),
+              ...(params.radius && { radius: params.radius })
+            };
           }
           case 'geocode':
           case 'map': {
diff --git a/lib/schema/README.md b/lib/schema/README.md
new file mode 100644
index 00000000..50644b4d
--- /dev/null
+++ b/lib/schema/README.md
@@ -0,0 +1,22 @@
+# AI Schema Compatibility Guidelines
+
+To ensure maximum compatibility with OpenAI-compatible endpoints (e.g., xAI, Grok, Gemini), all Zod schemas used for structured AI output must follow these rules.
+
+## Core Rules
+
+1.  **Avoid `z.literal()`**: Some endpoints do not support the `const` constraint in JSON Schema generated by `z.literal()`. Use `z.string()` and provide allowed values in the field description.
+2.  **Avoid `z.any()`**: Use explicit union types or more specific schemas to ensure validation reliability.
+3.  **Prefer Flat Optional Fields**: Avoid deeply nested required objects or complex discriminated unions. Instead, use a flat object with optional fields.
+4.  **Use Field Descriptions**: Convey conditional requirements (e.g., "Field X is required if `queryType` is 'search'") via the `.describe()` method on fields.
+5.  **Runtime Reconstruction**: If the frontend or downstream tools require a nested format (like standard GeoJSON), implement a reconstruction step in the application logic (e.g., in server actions) to transform the flat AI output into the desired structure.
+
+## Canonical Examples
+
+### Flat Schema with Conditional Requirements
+See `lib/schema/geospatial.tsx` for how `queryType` guides the use of other optional top-level fields.
+
+### Avoiding Const and Nested GeoJSON
+See `lib/schema/resolution-search.ts` for a flattened GeoJSON structure that avoids `z.literal()` and `z.any()`.
+
+### Runtime Reconstruction
+See `app/actions.tsx` (specifically the `processResolutionSearch` function) for how flattened features are reconstructed into a standard `FeatureCollection`.
diff --git a/lib/schema/geospatial.tsx b/lib/schema/geospatial.tsx
index c58b7f0a..4c6161e5 100644
--- a/lib/schema/geospatial.tsx
+++ b/lib/schema/geospatial.tsx
@@ -5,14 +5,18 @@ import { z } from 'zod';
 // queryType are conveyed to the LLM via the queryType description; runtime
 // behavior in the tool's execute() already tolerates missing fields per
 // queryType, so loosening the schema introduces no new failure modes.
+//
+// Compatibility Note: Following the established flattening pattern,
+// nested 'coordinates' object has been replaced with top-level 'latitude'
+// and 'longitude' fields.
 
 export const geospatialQuerySchema = z.object({
   queryType: z.enum(['search', 'geocode', 'reverse', 'directions', 'distance', 'map'])
     .describe(
       "Type of geospatial query. Set the corresponding fields: " +
-      "'search' → query (optionally coordinates, radius, maxResults); " +
+      "'search' → query (optionally latitude/longitude, radius, maxResults); " +
       "'geocode' → location (optionally maxResults); " +
-      "'reverse' → coordinates (optionally maxResults); " +
+      "'reverse' → latitude + longitude (optionally maxResults); " +
       "'directions' → origin + destination (optionally mode); " +
       "'distance' → origin + destination (optionally mode); " +
       "'map' → location."
@@ -25,12 +29,10 @@ export const geospatialQuerySchema = z.object({
     .min(1)
     .optional()
     .describe("Location to geocode or render as a map (used by 'geocode' and 'map')"),
-  coordinates: z.object({
-    latitude: z.number().min(-90).max(90),
-    longitude: z.number().min(-180).max(180)
-  })
-    .optional()
-    .describe("Coordinates (required for 'reverse', optional proximity hint for 'search')"),
+  latitude: z.number().min(-90).max(90).optional()
+    .describe("Latitude for reverse geocoding or map centering (used by 'reverse', optional for 'search')"),
+  longitude: z.number().min(-180).max(180).optional()
+    .describe("Longitude for reverse geocoding or map centering (used by 'reverse', optional for 'search')"),
   origin: z.string()
     .min(1)
     .optional()
diff --git a/lib/schema/related.tsx b/lib/schema/related.tsx
index 77fc3835..80c6d9f7 100644
--- a/lib/schema/related.tsx
+++ b/lib/schema/related.tsx
@@ -1,15 +1,12 @@
 import { DeepPartial } from 'ai'
 import { z } from 'zod'
 
+// Simplified schema to reduce nested complexity for better model compatibility.
+// Items are now plain strings instead of objects with a 'query' property.
 export const relatedSchema = z.object({
-  items: z
-    .array(
-      z.object({
-        query: z.string()
-      })
-    )
-    .length(3)
+  items: z.array(z.string()).length(3)
 })
+
 export type PartialRelated = DeepPartial<typeof relatedSchema>
 
 export type Related = z.infer<typeof relatedSchema>