diff --git a/pkg/agent/loop.go b/pkg/agent/loop.go
index 189d47aa7..bb923136d 100644
--- a/pkg/agent/loop.go
+++ b/pkg/agent/loop.go
@@ -768,11 +768,16 @@ func (al *AgentLoop) updateToolContexts(agent *AgentInstance, channel, chatID st
 // getOrCreateBlackboard returns the blackboard for a session, creating one if needed.
 func (al *AgentLoop) getOrCreateBlackboard(sessionKey string) *multiagent.Blackboard {
 	if v, ok := al.blackboards.Load(sessionKey); ok {
-		return v.(*multiagent.Blackboard)
+		if bb, ok := v.(*multiagent.Blackboard); ok {
+			return bb
+		}
 	}
 	bb := multiagent.NewBlackboard()
 	actual, _ := al.blackboards.LoadOrStore(sessionKey, bb)
-	return actual.(*multiagent.Blackboard)
+	if result, ok := actual.(*multiagent.Blackboard); ok {
+		return result
+	}
+	return bb
 }
 
 // maybeSummarize triggers summarization if the session history exceeds thresholds.
diff --git a/pkg/multiagent/blackboard_test.go b/pkg/multiagent/blackboard_test.go
index 45c7374d6..050361ba9 100644
--- a/pkg/multiagent/blackboard_test.go
+++ b/pkg/multiagent/blackboard_test.go
@@ -118,20 +118,18 @@ func TestBlackboard_Size(t *testing.T) {
 	}
 }
 
-func TestBlackboard_ConcurrentAccess(t *testing.T) {
+func TestBlackboard_ConcurrentAccess(_ *testing.T) {
 	bb := NewBlackboard()
 	var wg sync.WaitGroup
 
-	for i := 0; i < 100; i++ {
-		wg.Add(1)
-		go func(n int) {
-			defer wg.Done()
+	for range 100 {
+		wg.Go(func() {
 			key := "key"
 			bb.Set(key, "val", "agent")
 			bb.Get(key)
 			bb.List()
 			bb.Snapshot()
-		}(i)
+		})
 	}
 	wg.Wait()
 }
@@ -160,7 +158,7 @@ func TestBlackboardTool_Write(t *testing.T) {
 	bb := NewBlackboard()
 	tool := NewBlackboardTool(bb, "test-agent")
 
-	result := tool.Execute(context.Background(), map[string]interface{}{
+	result := tool.Execute(context.Background(), map[string]any{
 		"action": "write",
 		"key":    "task",
 		"value":  "implement feature",
@@ -183,7 +181,7 @@ func TestBlackboardTool_Read(t *testing.T) {
 	bb.Set("info", "hello", "other")
 	tool := NewBlackboardTool(bb, "reader")
 
-	result := tool.Execute(context.Background(), map[string]interface{}{
+	result := tool.Execute(context.Background(), map[string]any{
 		"action": "read",
 		"key":    "info",
 	})
@@ -199,7 +197,7 @@ func TestBlackboardTool_ReadMissing(t *testing.T) {
 	bb := NewBlackboard()
 	tool := NewBlackboardTool(bb, "reader")
 
-	result := tool.Execute(context.Background(), map[string]interface{}{
+	result := tool.Execute(context.Background(), map[string]any{
 		"action": "read",
 		"key":    "nope",
 	})
@@ -217,7 +215,7 @@ func TestBlackboardTool_List(t *testing.T) {
 	bb.Set("b", "2", "y")
 	tool := NewBlackboardTool(bb, "lister")
 
-	result := tool.Execute(context.Background(), map[string]interface{}{
+	result := tool.Execute(context.Background(), map[string]any{
 		"action": "list",
 	})
 	if result.IsError {
@@ -233,7 +231,7 @@ func TestBlackboardTool_Delete(t *testing.T) {
 	bb.Set("tmp", "val", "x")
 	tool := NewBlackboardTool(bb, "deleter")
 
-	result := tool.Execute(context.Background(), map[string]interface{}{
+	result := tool.Execute(context.Background(), map[string]any{
 		"action": "delete",
 		"key":    "tmp",
 	})
@@ -249,7 +247,7 @@ func TestBlackboardTool_InvalidAction(t *testing.T) {
 	bb := NewBlackboard()
 	tool := NewBlackboardTool(bb, "test")
 
-	result := tool.Execute(context.Background(), map[string]interface{}{
+	result := tool.Execute(context.Background(), map[string]any{
 		"action": "invalid",
 	})
 	if !result.IsError {
@@ -262,7 +260,7 @@ func TestBlackboardTool_MissingKey(t *testing.T) {
 	tool := NewBlackboardTool(bb, "test")
 
 	// read without key
-	result := tool.Execute(context.Background(), map[string]interface{}{
+	result := tool.Execute(context.Background(), map[string]any{
 		"action": "read",
 	})
 	if !result.IsError {
@@ -270,7 +268,7 @@ func TestBlackboardTool_MissingKey(t *testing.T) {
 	}
 
 	// write without key
-	result = tool.Execute(context.Background(), map[string]interface{}{
+	result = tool.Execute(context.Background(), map[string]any{
 		"action": "write",
 		"value":  "test",
 	})
@@ -279,7 +277,7 @@ func TestBlackboardTool_MissingKey(t *testing.T) {
 	}
 
 	// write without value
-	result = tool.Execute(context.Background(), map[string]interface{}{
+	result = tool.Execute(context.Background(), map[string]any{
 		"action": "write",
 		"key":    "k",
 	})
diff --git a/pkg/multiagent/blackboard_tool.go b/pkg/multiagent/blackboard_tool.go
index 4478b6d05..3f4d9e46f 100644
--- a/pkg/multiagent/blackboard_tool.go
+++ b/pkg/multiagent/blackboard_tool.go
@@ -23,27 +23,30 @@ func NewBlackboardTool(board *Blackboard, agentID string) *BlackboardTool {
 	}
 }
 
+// Name returns the tool name.
 func (t *BlackboardTool) Name() string { return "blackboard" }
 
+// Description returns a human-readable description of the tool.
 func (t *BlackboardTool) Description() string {
 	return "Read, write, list, or delete entries in the shared context blackboard. " +
 		"Use this to share information between agents in a multi-agent session."
 }
 
-func (t *BlackboardTool) Parameters() map[string]interface{} {
-	return map[string]interface{}{
+// Parameters returns the JSON Schema for the tool's input.
+func (t *BlackboardTool) Parameters() map[string]any {
+	return map[string]any{
 		"type": "object",
-		"properties": map[string]interface{}{
-			"action": map[string]interface{}{
+		"properties": map[string]any{
+			"action": map[string]any{
 				"type":        "string",
 				"enum":        []string{"read", "write", "list", "delete"},
 				"description": "The action to perform on the blackboard",
 			},
-			"key": map[string]interface{}{
+			"key": map[string]any{
 				"type":        "string",
 				"description": "The key to read, write, or delete (not required for list)",
 			},
-			"value": map[string]interface{}{
+			"value": map[string]any{
 				"type":        "string",
 				"description": "The value to write (only required for write action)",
 			},
@@ -52,10 +55,20 @@ func (t *BlackboardTool) Parameters() map[string]interface{} {
 	}
 }
 
-func (t *BlackboardTool) Execute(_ context.Context, args map[string]interface{}) *tools.ToolResult {
-	action, _ := args["action"].(string)
-	key, _ := args["key"].(string)
-	value, _ := args["value"].(string)
+// Execute runs the blackboard action specified in args.
+func (t *BlackboardTool) Execute(_ context.Context, args map[string]any) *tools.ToolResult {
+	action, ok := args["action"].(string)
+	if !ok {
+		action = ""
+	}
+	key, ok := args["key"].(string)
+	if !ok {
+		key = ""
+	}
+	value, ok := args["value"].(string)
+	if !ok {
+		value = ""
+	}
 
 	switch strings.ToLower(action) {
 	case "read":
@@ -85,11 +98,11 @@ func (t *BlackboardTool) Execute(_ context.Context, args map[string]interface{})
 			return tools.NewToolResult("Blackboard is empty")
 		}
 		var sb strings.Builder
-		sb.WriteString(fmt.Sprintf("Blackboard entries (%d):\n", len(keys)))
+		fmt.Fprintf(&sb, "Blackboard entries (%d):\n", len(keys))
 		for _, k := range keys {
 			entry := t.board.GetEntry(k)
 			if entry != nil {
-				sb.WriteString(fmt.Sprintf("- %s (by %s): %s\n", k, entry.Author, entry.Value))
+				fmt.Fprintf(&sb, "- %s (by %s): %s\n", k, entry.Author, entry.Value)
 			}
 		}
 		return tools.NewToolResult(sb.String())
diff --git a/pkg/multiagent/handoff.go b/pkg/multiagent/handoff.go
index 406bfdf84..cab5a9489 100644
--- a/pkg/multiagent/handoff.go
+++ b/pkg/multiagent/handoff.go
@@ -81,7 +81,7 @@ func ExecuteHandoff(ctx context.Context, resolver AgentResolver, board *Blackboa
 		Model:         target.Model,
 		Tools:         target.Tools,
 		MaxIterations: maxIter,
-		LLMOptions: map[string]interface{}{
+		LLMOptions: map[string]any{
 			"max_tokens":  4096,
 			"temperature": 0.7,
 		},
diff --git a/pkg/multiagent/handoff_test.go b/pkg/multiagent/handoff_test.go
index 0c08312b1..7b535ae29 100644
--- a/pkg/multiagent/handoff_test.go
+++ b/pkg/multiagent/handoff_test.go
@@ -15,7 +15,7 @@ type mockProvider struct {
 	err      error
 }
 
-func (m *mockProvider) Chat(_ context.Context, _ []providers.Message, _ []providers.ToolDefinition, _ string, _ map[string]interface{}) (*providers.LLMResponse, error) {
+func (m *mockProvider) Chat(_ context.Context, _ []providers.Message, _ []providers.ToolDefinition, _ string, _ map[string]any) (*providers.LLMResponse, error) {
 	if m.err != nil {
 		return nil, m.err
 	}
@@ -140,7 +140,7 @@ func TestHandoffTool_Execute(t *testing.T) {
 	bb := NewBlackboard()
 	tool := NewHandoffTool(resolver, bb, "main")
 
-	result := tool.Execute(context.Background(), map[string]interface{}{
+	result := tool.Execute(context.Background(), map[string]any{
 		"agent_id": "coder",
 		"task":     "write code",
 	})
@@ -159,7 +159,7 @@ func TestHandoffTool_MissingArgs(t *testing.T) {
 	tool := NewHandoffTool(resolver, bb, "main")
 
 	// Missing agent_id
-	result := tool.Execute(context.Background(), map[string]interface{}{
+	result := tool.Execute(context.Background(), map[string]any{
 		"task": "do something",
 	})
 	if !result.IsError {
@@ -167,7 +167,7 @@ func TestHandoffTool_MissingArgs(t *testing.T) {
 	}
 
 	// Missing task
-	result = tool.Execute(context.Background(), map[string]interface{}{
+	result = tool.Execute(context.Background(), map[string]any{
 		"agent_id": "coder",
 	})
 	if !result.IsError {
diff --git a/pkg/multiagent/handoff_tool.go b/pkg/multiagent/handoff_tool.go
index 03c85ff15..9f31dff33 100644
--- a/pkg/multiagent/handoff_tool.go
+++ b/pkg/multiagent/handoff_tool.go
@@ -28,8 +28,10 @@ func NewHandoffTool(resolver AgentResolver, board *Blackboard, fromAgentID strin
 	}
 }
 
+// Name returns the tool name.
 func (t *HandoffTool) Name() string { return "handoff" }
 
+// Description returns a dynamic description listing available target agents.
 func (t *HandoffTool) Description() string {
 	agents := t.resolver.ListAgents()
 	if len(agents) <= 1 {
@@ -42,31 +44,32 @@ func (t *HandoffTool) Description() string {
 		if a.ID == t.fromAgentID {
 			continue
 		}
-		sb.WriteString(fmt.Sprintf("- %s", a.ID))
+		fmt.Fprintf(&sb, "- %s", a.ID)
 		if a.Name != "" {
-			sb.WriteString(fmt.Sprintf(" (%s)", a.Name))
+			fmt.Fprintf(&sb, " (%s)", a.Name)
 		}
 		if a.Role != "" {
-			sb.WriteString(fmt.Sprintf(": %s", a.Role))
+			fmt.Fprintf(&sb, ": %s", a.Role)
 		}
 		sb.WriteString("\n")
 	}
 	return sb.String()
 }
 
-func (t *HandoffTool) Parameters() map[string]interface{} {
-	return map[string]interface{}{
+// Parameters returns the JSON Schema for the tool's input.
+func (t *HandoffTool) Parameters() map[string]any {
+	return map[string]any{
 		"type": "object",
-		"properties": map[string]interface{}{
-			"agent_id": map[string]interface{}{
+		"properties": map[string]any{
+			"agent_id": map[string]any{
 				"type":        "string",
 				"description": "The ID of the target agent to hand off to",
 			},
-			"task": map[string]interface{}{
+			"task": map[string]any{
 				"type":        "string",
 				"description": "The task description for the target agent",
 			},
-			"context": map[string]interface{}{
+			"context": map[string]any{
 				"type":        "object",
 				"description": "Optional key-value context to share via blackboard before handoff",
 			},
@@ -75,14 +78,22 @@ func (t *HandoffTool) Parameters() map[string]interface{} {
 	}
 }
 
+// SetContext updates the origin channel and chat ID for handoff routing.
 func (t *HandoffTool) SetContext(channel, chatID string) {
 	t.originChannel = channel
 	t.originChatID = chatID
 }
 
-func (t *HandoffTool) Execute(ctx context.Context, args map[string]interface{}) *tools.ToolResult {
-	agentID, _ := args["agent_id"].(string)
-	task, _ := args["task"].(string)
+// Execute delegates a task to the specified target agent.
+func (t *HandoffTool) Execute(ctx context.Context, args map[string]any) *tools.ToolResult {
+	agentID, ok := args["agent_id"].(string)
+	if !ok {
+		agentID = ""
+	}
+	task, ok := args["task"].(string)
+	if !ok {
+		task = ""
+	}
 
 	if agentID == "" {
 		return tools.ErrorResult("agent_id is required")
@@ -93,7 +104,7 @@ func (t *HandoffTool) Execute(ctx context.Context, args map[string]interface{})
 
 	// Parse optional context map
 	var contextMap map[string]string
-	if ctxRaw, ok := args["context"].(map[string]interface{}); ok {
+	if ctxRaw, ok := args["context"].(map[string]any); ok {
 		contextMap = make(map[string]string, len(ctxRaw))
 		for k, v := range ctxRaw {
 			contextMap[k] = fmt.Sprintf("%v", v)
diff --git a/pkg/multiagent/list_agents_tool.go b/pkg/multiagent/list_agents_tool.go
index 23e2ad6f3..f46838848 100644
--- a/pkg/multiagent/list_agents_tool.go
+++ b/pkg/multiagent/list_agents_tool.go
@@ -18,34 +18,38 @@ func NewListAgentsTool(resolver AgentResolver) *ListAgentsTool {
 	return &ListAgentsTool{resolver: resolver}
 }
 
+// Name returns the tool name.
 func (t *ListAgentsTool) Name() string { return "list_agents" }
 
+// Description returns a human-readable description of the tool.
 func (t *ListAgentsTool) Description() string {
 	return "List all available agents with their IDs, names, and roles."
 }
 
-func (t *ListAgentsTool) Parameters() map[string]interface{} {
-	return map[string]interface{}{
+// Parameters returns the JSON Schema for the tool's input.
+func (t *ListAgentsTool) Parameters() map[string]any {
+	return map[string]any{
 		"type":       "object",
-		"properties": map[string]interface{}{},
+		"properties": map[string]any{},
 	}
 }
 
-func (t *ListAgentsTool) Execute(_ context.Context, _ map[string]interface{}) *tools.ToolResult {
+// Execute lists all registered agents with their metadata.
+func (t *ListAgentsTool) Execute(_ context.Context, _ map[string]any) *tools.ToolResult {
 	agents := t.resolver.ListAgents()
 	if len(agents) == 0 {
 		return tools.NewToolResult("No agents registered.")
 	}
 
 	var sb strings.Builder
-	sb.WriteString(fmt.Sprintf("Available agents (%d):\n", len(agents)))
+	fmt.Fprintf(&sb, "Available agents (%d):\n", len(agents))
 	for _, a := range agents {
-		sb.WriteString(fmt.Sprintf("- ID: %s", a.ID))
+		fmt.Fprintf(&sb, "- ID: %s", a.ID)
 		if a.Name != "" {
-			sb.WriteString(fmt.Sprintf(", Name: %s", a.Name))
+			fmt.Fprintf(&sb, ", Name: %s", a.Name)
 		}
 		if a.Role != "" {
-			sb.WriteString(fmt.Sprintf(", Role: %s", a.Role))
+			fmt.Fprintf(&sb, ", Role: %s", a.Role)
 		}
 		sb.WriteString("\n")
 	}
diff --git a/pkg/routing/agent_id.go b/pkg/routing/agent_id.go
index bcf2f0dc0..a6e6e881e 100644
--- a/pkg/routing/agent_id.go
+++ b/pkg/routing/agent_id.go
@@ -5,6 +5,7 @@ import (
 	"strings"
 )
 
+// Agent ID defaults and constraints.
 const (
 	DefaultAgentID   = "main"
 	DefaultMainKey   = "main"
diff --git a/pkg/routing/route.go b/pkg/routing/route.go
index 9eb060c53..9b69bf366 100644
--- a/pkg/routing/route.go
+++ b/pkg/routing/route.go
@@ -21,8 +21,8 @@ type ResolvedRoute struct {
 	AgentID        string
 	Channel        string
 	AccountID      string
-	SessionKey     string
-	MainSessionKey string
+	SessionKey     string `json:"session_key"`      //nolint:gosec // G117: not a secret, this is a session identifier
+	MainSessionKey string `json:"main_session_key"` //nolint:gosec // G117: not a secret, this is a session identifier
 	MatchedBy      string // "binding.peer", "binding.peer.parent", "binding.guild", "binding.team", "binding.account", "binding.channel", "default"
 }
 
@@ -141,7 +141,7 @@ func matchesAccountID(matchAccountID, actual string) bool {
 	if trimmed == "*" {
 		return true
 	}
-	return strings.ToLower(trimmed) == strings.ToLower(actual)
+	return strings.EqualFold(trimmed, actual)
 }
 
 func (r *RouteResolver) findPeerMatch(bindings []config.AgentBinding, peer *RoutePeer) *config.AgentBinding {
diff --git a/pkg/routing/session_key.go b/pkg/routing/session_key.go
index e12f0d1d8..cb2469a10 100644
--- a/pkg/routing/session_key.go
+++ b/pkg/routing/session_key.go
@@ -8,6 +8,7 @@ import (
 // DMScope controls DM session isolation granularity.
 type DMScope string
 
+// DM scope constants control session isolation granularity.
 const (
 	DMScopeMain                  DMScope = "main"
 	DMScopePerPeer               DMScope = "per-peer"
@@ -86,6 +87,8 @@ func BuildAgentPeerSessionKey(params SessionKeyParams) string {
 			if peerID != "" {
 				return fmt.Sprintf("agent:%s:direct:%s", agentID, peerID)
 			}
+		default:
+			// DMScopeMain or unrecognized: fall through to main session key
 		}
 		return BuildAgentMainSessionKey(agentID)
 	}