diff --git a/pkg/agent/loop.go b/pkg/agent/loop.go
index 05ccbe449..cfffce606 100644
--- a/pkg/agent/loop.go
+++ b/pkg/agent/loop.go
@@ -81,6 +81,7 @@ type processOptions struct {
 	ForcedSkills            []string            // Skills explicitly requested for this message
 	SystemPromptOverride    string              // Override the default system prompt (Used by SubTurns)
 	Media                   []string            // media:// refs from inbound message
+	IsVoice                 bool                // True if this message comes from an audio/voice call
 	InitialSteeringMessages []providers.Message // Steering messages from refactor/agent
 	DefaultResponse         string              // Response when LLM returns empty
 	EnableSummary           bool                // Whether to trigger summarization
@@ -1311,17 +1312,25 @@ func (al *AgentLoop) processMessage(ctx context.Context, msg bus.InboundMessage)
 			"route_channel": route.Channel,
 		})
 
+	isVoice := msg.Metadata != nil && msg.Metadata["is_voice"] == "true"
+	var systemPromptOverride string
+	if isVoice {
+		systemPromptOverride = "You are a helpful AI assistant. The user is speaking to you over voice chat. Reply in a concise, conversational, and natural oral style suitable for text-to-speech. Get straight to the point. Do not use Markdown, emojis, asterisks, or code blocks."
+	}
+
 	opts := processOptions{
-		SessionKey:        sessionKey,
-		Channel:           msg.Channel,
-		ChatID:            msg.ChatID,
-		SenderID:          msg.SenderID,
-		SenderDisplayName: msg.Sender.DisplayName,
-		UserMessage:       msg.Content,
-		Media:             msg.Media,
-		DefaultResponse:   defaultResponse,
-		EnableSummary:     true,
-		SendResponse:      false,
+		SessionKey:           sessionKey,
+		Channel:              msg.Channel,
+		ChatID:               msg.ChatID,
+		SenderID:             msg.SenderID,
+		SenderDisplayName:    msg.Sender.DisplayName,
+		UserMessage:          msg.Content,
+		SystemPromptOverride: systemPromptOverride,
+		Media:                msg.Media,
+		IsVoice:              isVoice,
+		DefaultResponse:      defaultResponse,
+		EnableSummary:        true,
+		SendResponse:         false,
 	}
 
 	// context-dependent commands check their own Runtime fields and report
@@ -1640,7 +1649,10 @@ func (al *AgentLoop) runTurn(ctx context.Context, ts *turnState) (turnResult, er
 	messages = resolveMediaRefs(messages, al.mediaStore, maxMediaSize)
 
 	if !ts.opts.NoHistory {
-		toolDefs := ts.agent.Tools.ToProviderDefs()
+		var toolDefs []providers.ToolDefinition
+		if !ts.opts.IsVoice {
+			toolDefs = ts.agent.Tools.ToProviderDefs()
+		}
 		if isOverContextBudget(ts.agent.ContextWindow, messages, toolDefs, ts.agent.MaxTokens) {
 			logger.WarnCF("agent", "Proactive compression: context budget exceeded before LLM call",
 				map[string]any{"session_key": ts.sessionKey})
@@ -1779,7 +1791,10 @@ turnLoop:
 			})
 
 		gracefulTerminal, _ := ts.gracefulInterruptRequested()
-		providerToolDefs := ts.agent.Tools.ToProviderDefs()
+		var providerToolDefs []providers.ToolDefinition
+		if !ts.opts.IsVoice {
+			providerToolDefs = ts.agent.Tools.ToProviderDefs()
+		}
 
 		// Native web search support (from HEAD)
 		_, hasWebSearch := ts.agent.Tools.Get("web_search")
diff --git a/pkg/utils/string.go b/pkg/utils/string.go
index dbaafdb7f..99337b557 100644
--- a/pkg/utils/string.go
+++ b/pkg/utils/string.go
@@ -65,3 +65,8 @@ func DerefStr(s *string, fallback string) string {
 	}
 	return *s
 }
+
+// IsTruncationDisabled returns whether truncation is disabled globally
+func IsTruncationDisabled() bool {
+return disableTruncation.Load()
+}