diff --git a/openai/openai.go b/openai/openai.go
index 010481518..556c2fd8e 100644
--- a/openai/openai.go
+++ b/openai/openai.go
@@ -11,6 +11,7 @@ import (
 	"fmt"
 	"log/slog"
 	"net/http"
+	"slices"
 	"strings"
 	"time"
 
@@ -634,6 +635,7 @@ func FromChatRequest(r ChatCompletionRequest, thinking ...*model.Thinking) (*api
 			}
 			messages = append(messages, api.Message{Role: msg.Role, Content: content, Thinking: msg.Reasoning, ToolCalls: toolCalls, ToolName: toolName, ToolCallID: msg.ToolCallID})
 		case []any:
+			start := len(messages)
 			for _, c := range content {
 				data, ok := c.(map[string]any)
 				if !ok {
@@ -682,6 +684,25 @@ func FromChatRequest(r ChatCompletionRequest, thinking ...*model.Thinking) (*api
 					return nil, errors.New("invalid message format")
 				}
 			}
+			// a tool message is a single result, so every message built from it
+			// keeps the tool call it answers. text parts are merged into one
+			// message; parts with images stay split so each image keeps its
+			// position among the text
+			if strings.ToLower(msg.Role) == "tool" {
+				parts := messages[start:]
+				if slices.ContainsFunc(parts, func(m api.Message) bool { return len(m.Images) > 0 }) {
+					for i := range parts {
+						parts[i].ToolName = toolName
+						parts[i].ToolCallID = msg.ToolCallID
+					}
+				} else if len(parts) > 0 || toolName != "" || msg.ToolCallID != "" {
+					var sb strings.Builder
+					for _, part := range parts {
+						sb.WriteString(part.Content)
+					}
+					messages = append(messages[:start], api.Message{Role: msg.Role, Content: sb.String(), ToolName: toolName, ToolCallID: msg.ToolCallID})
+				}
+			}
 			// since we might have added multiple messages above, if we have tools
 			// calls we'll add them to the last message
 			if len(messages) > 0 && len(msg.ToolCalls) > 0 {
diff --git a/openai/openai_test.go b/openai/openai_test.go
index c92e19563..59be1bbab 100644
--- a/openai/openai_test.go
+++ b/openai/openai_test.go
@@ -157,6 +157,118 @@ func TestFromChatRequest_WithImage(t *testing.T) {
 	}
 }
 
+func TestFromChatRequest_ToolMessageArrayContent(t *testing.T) {
+	var req ChatCompletionRequest
+	if err := json.Unmarshal([]byte(`{"model":"test-model","messages":[
+		{"role":"assistant","tool_calls":[{"id":"call_1","type":"function","function":{"name":"get_weather","arguments":"{}"}}]},
+		{"role":"tool","tool_call_id":"call_1","content":[{"type":"text","text":"sunny [img]"},{"type":"text","text":", 72F [img-99]"}]}
+	]}`), &req); err != nil {
+		t.Fatal(err)
+	}
+
+	result, err := FromChatRequest(req)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	// text parts are merged into one result; tool text is kept as sent
+	if len(result.Messages) != 2 {
+		t.Fatalf("expected 2 messages, got %d", len(result.Messages))
+	}
+	tool := result.Messages[1]
+	if tool.Role != "tool" || tool.ToolCallID != "call_1" || tool.ToolName != "get_weather" || tool.Content != "sunny [img], 72F [img-99]" {
+		t.Errorf("expected tool message for call_1/get_weather, got role=%q id=%q name=%q content=%q", tool.Role, tool.ToolCallID, tool.ToolName, tool.Content)
+	}
+}
+
+func TestFromChatRequest_ToolMessageArrayContentWithImages(t *testing.T) {
+	const image2 = `iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNkYPhfDwAChwGA60e6kgAAAABJRU5ErkJggg==`
+	imgData, _ := base64.StdEncoding.DecodeString(image)
+	img2Data, _ := base64.StdEncoding.DecodeString(image2)
+
+	req := ChatCompletionRequest{
+		Model: "test-model",
+		Messages: []Message{
+			{Role: "user", Content: "What's in the screenshot?"},
+			{
+				Role: "assistant",
+				ToolCalls: []ToolCall{{
+					ID:   "call_1",
+					Type: "function",
+					Function: struct {
+						Name      string `json:"name"`
+						Arguments string `json:"arguments"`
+					}{Name: "screenshot", Arguments: "{}"},
+				}},
+			},
+			{
+				Role:       "tool",
+				ToolCallID: "call_1",
+				Content: []any{
+					map[string]any{"type": "text", "text": "Before: "},
+					map[string]any{
+						"type":      "image_url",
+						"image_url": map[string]any{"url": prefix + image},
+					},
+					map[string]any{"type": "text", "text": " After: "},
+					map[string]any{
+						"type":      "image_url",
+						"image_url": map[string]any{"url": prefix + image2},
+					},
+				},
+			},
+		},
+	}
+
+	result, err := FromChatRequest(req)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	// parts with images stay split in order, each answering the same call
+	if len(result.Messages) != 6 {
+		t.Fatalf("expected 6 messages, got %d", len(result.Messages))
+	}
+	wantContent := []string{"Before: ", "", " After: ", ""}
+	wantImages := [][]byte{nil, imgData, nil, img2Data}
+	for i, msg := range result.Messages[2:] {
+		if msg.Role != "tool" || msg.ToolCallID != "call_1" || msg.ToolName != "screenshot" {
+			t.Errorf("part %d: expected tool message for call_1/screenshot, got role=%q id=%q name=%q", i, msg.Role, msg.ToolCallID, msg.ToolName)
+		}
+		if msg.Content != wantContent[i] {
+			t.Errorf("part %d: expected content %q, got %q", i, wantContent[i], msg.Content)
+		}
+		if wantImages[i] == nil && len(msg.Images) != 0 || wantImages[i] != nil && (len(msg.Images) != 1 || string(msg.Images[0]) != string(wantImages[i])) {
+			t.Errorf("part %d: unexpected images, got %d", i, len(msg.Images))
+		}
+	}
+}
+
+func TestFromChatRequest_ToolMessageEmptyArrayContent(t *testing.T) {
+	var req ChatCompletionRequest
+	if err := json.Unmarshal([]byte(`{"model":"test-model","messages":[
+		{"role":"assistant","tool_calls":[{"id":"call_1","type":"function","function":{"name":"screenshot","arguments":"{}"}}]},
+		{"role":"tool","tool_call_id":"call_1","content":[]},
+		{"role":"tool","content":[]}
+	]}`), &req); err != nil {
+		t.Fatal(err)
+	}
+
+	result, err := FromChatRequest(req)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	// the empty result without a call id or name is skipped
+	if len(result.Messages) != 2 {
+		t.Fatalf("expected 2 messages, got %d", len(result.Messages))
+	}
+	tool := result.Messages[1]
+	if tool.Role != "tool" || tool.ToolCallID != "call_1" || tool.ToolName != "screenshot" || tool.Content != "" {
+		t.Errorf("expected empty tool message for call_1/screenshot, got role=%q id=%q name=%q content=%q", tool.Role, tool.ToolCallID, tool.ToolName, tool.Content)
+	}
+}
+
 func TestFromCompleteRequest_Basic(t *testing.T) {
 	temp := float32(0.8)
 	req := CompletionRequest{