diff --git a/packages/core/ios/Sources/DdFlagsImplementation.swift b/packages/core/ios/Sources/DdFlagsImplementation.swift
index d5f638651..26b13727f 100644
--- a/packages/core/ios/Sources/DdFlagsImplementation.swift
+++ b/packages/core/ios/Sources/DdFlagsImplementation.swift
@@ -58,7 +58,7 @@ public class DdFlagsImplementation: NSObject {
     public func setEvaluationContext(_ clientName: String, targetingKey: String, attributes: NSDictionary, resolve: @escaping ((Any?) -> Void), reject: @escaping ((String?, String?, NSError?) -> Void)) {
         let client = getClient(name: clientName)
         guard let clientInternal = client as? FlagsClientInternal else {
-            reject(nil, "CLIENT_NOT_INITIALIZED", nil)
+            reject("CLIENT_NOT_INITIALIZED", "Flags client '\(clientName)' is not properly initialized. Make sure the Datadog SDK has been initialized and Flags.enable() has been called.", nil)
             return
         }
 
@@ -68,7 +68,7 @@ public class DdFlagsImplementation: NSObject {
             switch result {
             case .success:
                 guard let flagsSnapshot = clientInternal.getFlagAssignments() else {
-                    reject(nil, "CLIENT_NOT_INITIALIZED", nil)
+                    reject("CLIENT_NOT_INITIALIZED", "Failed to retrieve feature flags for client '\(clientName)'. Make sure the client has been properly initialized.", nil)
                     return
                 }
 
@@ -81,17 +81,22 @@ public class DdFlagsImplementation: NSObject {
                 resolve(serializedFlagsSnapshot)
             case .failure(let error):
                 var errorCode: String
+                var errorMessage: String
                 switch (error) {
                 case .clientNotInitialized:
                     errorCode = "CLIENT_NOT_INITIALIZED"
+                    errorMessage = "Failed to retrieve feature flags for client '\(clientName)'. Make sure the client has been properly initialized."
                 case .invalidConfiguration:
                     errorCode = "INVALID_CONFIGURATION"
+                    errorMessage = "The flags configuration for client '\(clientName)' is invalid. Check that all required parameters are provided."
                 case .invalidResponse:
                     errorCode = "INVALID_RESPONSE"
+                    errorMessage = "The flags service returned an invalid response for client '\(clientName)'."
                 case .networkError:
                     errorCode = "NETWORK_ERROR"
+                    errorMessage = "A network error occurred while fetching feature flags for client '\(clientName)'."
                 }
-                reject(nil, errorCode, error as NSError)
+                reject(errorCode, errorMessage, error as NSError)
             }
         }
     }
@@ -99,11 +104,11 @@ public class DdFlagsImplementation: NSObject {
     @objc
     public func trackEvaluation(_ clientName: String, key: String, rawFlag: NSDictionary, targetingKey: String, attributes: NSDictionary, resolve: RCTPromiseResolveBlock, reject: RCTPromiseRejectBlock) {
         guard let client = getClient(name: clientName) as? FlagsClientInternal else {
-            reject(nil, "CLIENT_NOT_INITIALIZED", nil)
+            reject("CLIENT_NOT_INITIALIZED", "Flags client '\(clientName)' is not properly initialized. Make sure the Datadog SDK has been initialized and Flags.enable() has been called.", nil)
             return
         }
         guard let flagAssignment = rawFlag.asFlagAssignment() else {
-            reject(nil, "INVALID_FLAG_ASSIGNMENT", nil)
+            reject("INVALID_FLAG_ASSIGNMENT", "Failed to parse correct flag assignment from the provided raw flag data.", nil)
             return
         }
 
diff --git a/packages/core/ios/Tests/DdFlagsTests.swift b/packages/core/ios/Tests/DdFlagsTests.swift
index 45849c8d8..3fca72ddc 100644
--- a/packages/core/ios/Tests/DdFlagsTests.swift
+++ b/packages/core/ios/Tests/DdFlagsTests.swift
@@ -98,7 +98,8 @@ class DdFlagsTests: XCTestCase {
             XCTFail("Should not resolve")
             expectation.fulfill()
         }, reject: { code, message, error in
-            XCTAssertEqual(message, "CLIENT_NOT_INITIALIZED")
+            XCTAssertEqual(code, "CLIENT_NOT_INITIALIZED")
+            XCTAssertNotNil(message)
             expectation.fulfill()
         })
 
@@ -117,7 +118,8 @@ class DdFlagsTests: XCTestCase {
             XCTFail("Should not resolve")
             expectation.fulfill()
         }, reject: { code, message, error in
-            XCTAssertEqual(message, "NETWORK_ERROR")
+            XCTAssertEqual(code, "NETWORK_ERROR")
+            XCTAssertNotNil(message)
             expectation.fulfill()
         })
 
@@ -164,7 +166,8 @@ class DdFlagsTests: XCTestCase {
             XCTFail("Should not resolve")
             expectation.fulfill()
         }, reject: { code, message, error in
-            XCTAssertEqual(message, "INVALID_FLAG_ASSIGNMENT")
+            XCTAssertEqual(code, "INVALID_FLAG_ASSIGNMENT")
+            XCTAssertNotNil(message)
             expectation.fulfill()
         })
 
diff --git a/packages/core/src/flags/FlagsClient.ts b/packages/core/src/flags/FlagsClient.ts
index 1d1f87413..62284cc40 100644
--- a/packages/core/src/flags/FlagsClient.ts
+++ b/packages/core/src/flags/FlagsClient.ts
@@ -69,7 +69,7 @@ export class FlagsClient {
             if (error instanceof Error) {
                 InternalLog.log(
                     `Error setting flag evaluation context: ${error.message}`,
-                    SdkVerbosity.ERROR
+                    SdkVerbosity.WARN
                 );
             }
 
diff --git a/packages/core/src/flags/__tests__/FlagsClient.test.ts b/packages/core/src/flags/__tests__/FlagsClient.test.ts
index f84539327..06903099c 100644
--- a/packages/core/src/flags/__tests__/FlagsClient.test.ts
+++ b/packages/core/src/flags/__tests__/FlagsClient.test.ts
@@ -96,7 +96,9 @@ describe('FlagsClient', () => {
 
         it('should throw an error if there is an error setting the evaluation context', async () => {
             NativeModules.DdFlags.setEvaluationContext.mockRejectedValueOnce(
-                new Error('NETWORK_ERROR')
+                new Error(
+                    "A network error occurred while fetching feature flags for client 'default'."
+                )
             );
 
             const flagsClient = DdFlags.getClient();
@@ -106,11 +108,13 @@ describe('FlagsClient', () => {
                     targetingKey: 'test-user-1',
                     attributes: { country: 'US' }
                 })
-            ).rejects.toThrow('NETWORK_ERROR');
+            ).rejects.toThrow(
+                "A network error occurred while fetching feature flags for client 'default'."
+            );
 
             expect(InternalLog.log).toHaveBeenCalledWith(
-                'Error setting flag evaluation context: NETWORK_ERROR',
-                SdkVerbosity.ERROR
+                "Error setting flag evaluation context: A network error occurred while fetching feature flags for client 'default'.",
+                SdkVerbosity.WARN
             );
         });
     });