feat: surface MCP server connect health to operators and agents

Every connect attempt (discovery, refresh, and the per-agent-run wiring) now
records its outcome on the server row: last_connect_at/ok/err, written through
a change-deduped update so per-run wiring does not amplify writes. The MCP page
shows a health chip per card (ok with time, or the failure reason), and a new
read-only mcp_status tool (bound to auto, worker and pentest) lets a worker
notice that a server it expected is down and say so instead of silently
degrading while the cached tool count keeps the card looking healthy.

Closes #38

db/config.go

@@ -822,11 +822,14 @@ type MCPServer struct {
 	Enabled        bool            `json:"enabled"`
 	Insecure       bool            `json:"insecure"`        // http: skip TLS cert verification (self-signed servers, issue #108)
 	TimeoutSeconds int             `json:"timeout_seconds"` // http: per-request timeout in seconds; 0 = default 120
+	LastConnectAt  *time.Time      `json:"last_connect_at,omitempty"`
+	LastConnectOK  *bool           `json:"last_connect_ok,omitempty"`
+	LastConnectErr *string         `json:"last_connect_err,omitempty"`
 	Tools          []string        `json:"tools,omitempty"` // cached tool names (mcp_tools_cache)
 }
 
 func (d *DB) ListMCP() ([]*MCPServer, error) {
-	rows, err := d.Query(`SELECT id,name,transport,COALESCE(command,''),args,env,COALESCE(url,''),enabled,insecure,COALESCE(timeout_seconds,120) FROM mcp_servers ORDER BY id`)
+	rows, err := d.Query(`SELECT id,name,transport,COALESCE(command,''),args,env,COALESCE(url,''),enabled,insecure,COALESCE(timeout_seconds,120),last_connect_at,last_connect_ok,last_connect_err FROM mcp_servers ORDER BY id`)
 	if err != nil {
 		return nil, err
 	}
@@ -834,7 +837,7 @@ func (d *DB) ListMCP() ([]*MCPServer, error) {
 	for rows.Next() {
 		var m MCPServer
 		var args, env []byte
-		if err := rows.Scan(&m.ID, &m.Name, &m.Transport, &m.Command, &args, &env, &m.URL, &m.Enabled, &m.Insecure, &m.TimeoutSeconds); err != nil {
+		if err := rows.Scan(&m.ID, &m.Name, &m.Transport, &m.Command, &args, &env, &m.URL, &m.Enabled, &m.Insecure, &m.TimeoutSeconds, &m.LastConnectAt, &m.LastConnectOK, &m.LastConnectErr); err != nil {
 			rows.Close()
 			return nil, err
 		}
@@ -914,6 +917,17 @@ ON CONFLICT (server_id, tool_name) DO UPDATE SET description=EXCLUDED.descriptio
 	return tx.Commit()
 }
 
+// UpdateMCPHealth records the outcome of one connect attempt. The WHERE clause
+// skips the write when nothing changed, so per-run wiring does not amplify writes.
+func (d *DB) UpdateMCPHealth(id int64, ok bool, errMsg string) error {
+	_, err := d.Exec(`UPDATE mcp_servers
+		SET last_connect_at = now(), last_connect_ok = $2, last_connect_err = NULLIF($3, '')
+		WHERE id = $1
+		  AND (last_connect_ok IS DISTINCT FROM $2 OR last_connect_err IS DISTINCT FROM NULLIF($3, '') OR last_connect_at IS NULL)`,
+		id, ok, errMsg)
+	return err
+}
+
 func (d *DB) SaveMCP(m *MCPServer) (int64, error) {
 	args, env := string(m.Args), string(m.Env)
 	if args == "" {

db/schema.sql

@@ -863,6 +863,11 @@ ALTER TABLE mcp_servers ADD COLUMN IF NOT EXISTS insecure BOOLEAN NOT NULL DEFAU
 -- servers whose tools legitimately run minutes (e.g. binary reverse engineering) need room
 -- beyond the default without forcing every other server to wait as long.
 ALTER TABLE mcp_servers ADD COLUMN IF NOT EXISTS timeout_seconds INT NOT NULL DEFAULT 120;
+-- Connect health: updated on every connect attempt (discovery, refresh, per-agent-run
+-- wiring). NULL = never attempted. The WHERE-deduped update avoids write amplification.
+ALTER TABLE mcp_servers ADD COLUMN IF NOT EXISTS last_connect_at TIMESTAMPTZ;
+ALTER TABLE mcp_servers ADD COLUMN IF NOT EXISTS last_connect_ok BOOLEAN;
+ALTER TABLE mcp_servers ADD COLUMN IF NOT EXISTS last_connect_err TEXT;
 DROP TRIGGER IF EXISTS trg_mcp_upd ON mcp_servers;
 CREATE TRIGGER trg_mcp_upd BEFORE UPDATE ON mcp_servers
     FOR EACH ROW EXECUTE FUNCTION set_updated_at();

server/assembly.go

@@ -86,14 +86,17 @@ func wireAgentAugment(pg *db.DB, skillDir string, hostTools func() ([]actool.Cor
 				cl, err := connectMCP(ctx, m)
 				if err != nil {
 					log.Printf("[mcp] %s connect failed: %v", m.Name, err)
+					_ = pg.UpdateMCPHealth(m.ID, false, "connect: "+err.Error())
 					continue
 				}
 				closers = append(closers, cl)
 				ts, err := cl.Tools(ctx)
 				if err != nil {
 					log.Printf("[mcp] %s tools/list failed: %v", m.Name, err)
+					_ = pg.UpdateMCPHealth(m.ID, false, "tools/list: "+err.Error())
 					continue
 				}
+				_ = pg.UpdateMCPHealth(m.ID, true, "")
 				for _, t := range ts {
 					extra = append(extra, t)
 					allNames = append(allNames, t.Name())

server/mcp_health_test.go

@@ -0,0 +1,65 @@
+package server
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/Autumn-27/artex/db"
+)
+
+// The health columns must reflect the outcome of every connect attempt and
+// transition cleanly down -> ok, so the UI badge and the mcp_status tool can
+// show operators why a server's tools are missing (#38).
+func TestMCPHealthStateTransitions(t *testing.T) {
+	s, _, _ := trafficEvidenceServer(t)
+	pg := s.m.pg
+
+	row := &db.MCPServer{Name: "health-test", Transport: "http", URL: "http://127.0.0.1:1/mcp", Enabled: true}
+	id, err := pg.SaveMCP(row)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { _ = pg.DeleteMCP(id) })
+
+	found := listMCPByName(t, pg, "health-test")
+	if found.LastConnectAt != nil || found.LastConnectOK != nil || found.LastConnectErr != nil {
+		t.Fatalf("fresh server should have no health state, got %+v", found)
+	}
+
+	if err := pg.UpdateMCPHealth(id, false, "connect: no route to host"); err != nil {
+		t.Fatal(err)
+	}
+	found = listMCPByName(t, pg, "health-test")
+	if found.LastConnectOK == nil || *found.LastConnectOK {
+		t.Fatal("expected last_connect_ok = false after a failed connect")
+	}
+	if found.LastConnectErr == nil || !strings.Contains(*found.LastConnectErr, "no route") {
+		t.Fatalf("expected the failure reason, got %+v", found.LastConnectErr)
+	}
+
+	if err := pg.UpdateMCPHealth(id, true, ""); err != nil {
+		t.Fatal(err)
+	}
+	found = listMCPByName(t, pg, "health-test")
+	if found.LastConnectOK == nil || !*found.LastConnectOK {
+		t.Fatal("expected last_connect_ok = true after a successful connect")
+	}
+	if found.LastConnectErr != nil {
+		t.Fatalf("expected the error cleared on success, got %q", *found.LastConnectErr)
+	}
+}
+
+func listMCPByName(t *testing.T, pg *db.DB, name string) *db.MCPServer {
+	t.Helper()
+	rows, err := pg.ListMCP()
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, r := range rows {
+		if r.Name == name {
+			return r
+		}
+	}
+	t.Fatalf("server %s not found", name)
+	return nil
+}

server/mcpdiscover.go

@@ -49,13 +49,16 @@ func connectMCP(ctx context.Context, m *db.MCPServer) (mcpClient, error) {
 func (s *Server) discoverAndCacheMCP(ctx context.Context, m *db.MCPServer) error {
 	cl, err := connectMCP(ctx, m)
 	if err != nil {
+		_ = s.m.pg.UpdateMCPHealth(m.ID, false, err.Error())
 		return err
 	}
 	defer cl.Close()
 	ts, err := cl.Tools(ctx)
 	if err != nil {
+		_ = s.m.pg.UpdateMCPHealth(m.ID, false, err.Error())
 		return err
 	}
+	_ = s.m.pg.UpdateMCPHealth(m.ID, true, "")
 	tools := make([]db.MCPTool, 0, len(ts))
 	for _, t := range ts {
 		tools = append(tools, db.MCPTool{Name: t.Name(), Description: t.Description()})

server/orchestration.go

@@ -484,7 +484,12 @@ func (s *Server) seedOrchestrationTools() {
 	}
 	for _, t := range s.platformTools() {
 		schema, _ := json.Marshal(t.InputSchema())
-		_ = s.m.PG().SeedTool(t.Name(), t.Description(), schema, autoAgents)
+		bindings := autoAgents
+		if t.Name() == "mcp_status" {
+			// health visibility is for the executors too, not just the platform agent
+			bindings = json.RawMessage(`["auto","worker","pentest"]`)
+		}
+		_ = s.m.PG().SeedTool(t.Name(), t.Description(), schema, bindings)
 	}
 	s.refreshBuiltinToolSchemas()
 	s.seedAutoDefaultBindings()

server/platform_tools.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"time"
 
 	"github.com/Autumn-27/artex/db"
 	actool "github.com/Autumn-27/norma/tool"
@@ -17,6 +18,7 @@ import (
 
 func (s *Server) platformTools() []actool.CoreTool {
 	return []actool.CoreTool{
+		s.toolMCPStatus(),
 		s.toolCreateSkill(),
 		s.toolUpdateSkillFile(),
 		s.toolCreateCustomTool(),
@@ -243,6 +245,55 @@ func (s *Server) toolUpdateCustomTool() actool.CoreTool {
 		})
 }
 
+// ---- MCP health ----
+
+// toolMCPStatus reports each MCP server's last connect outcome so a worker can
+// notice a missing server (and say so) instead of silently degrading when the
+// catalog is cached but the server is unreachable.
+func (s *Server) toolMCPStatus() actool.CoreTool {
+	return wrTool("mcp_status",
+		"Report the health of every configured MCP server: name, transport, enabled, cached tool count, and the outcome of the last connect attempt (time, ok/error). Use this when tools you expect are missing or before relying on a skill-gated server.",
+		map[string]any{"type": "object", "properties": map[string]any{}},
+		func(ctx context.Context, in json.RawMessage) (actool.Result, error) {
+			servers, err := s.m.pg.ListMCP()
+			if err != nil {
+				return actool.Errorf("Error: " + err.Error()), nil
+			}
+			var b strings.Builder
+			fmt.Fprintf(&b, "%d MCP server(s):\n", len(servers))
+			for _, m := range servers {
+				status := "never connected"
+				switch {
+				case m.LastConnectOK != nil && *m.LastConnectOK:
+					status = "connected ok"
+				case m.LastConnectOK != nil && !*m.LastConnectOK:
+					status = "DOWN: " + strings.TrimSpace(coalesceStr(m.LastConnectErr, "connect failed"))
+				}
+				fmt.Fprintf(&b, "- %s [%s, %s, %d cached tools]: %s", m.Name, m.Transport, enabledWord(m.Enabled), len(m.Tools), status)
+				if m.LastConnectAt != nil {
+					fmt.Fprintf(&b, " (last attempt %s)", m.LastConnectAt.UTC().Format(time.RFC3339))
+				}
+				b.WriteByte('\n')
+			}
+			b.WriteString("If a server you need is DOWN, tell the operator in your final report instead of working around it.")
+			return actool.Text(b.String()), nil
+		})
+}
+
+func coalesceStr(p *string, fallback string) string {
+	if p == nil {
+		return fallback
+	}
+	return *p
+}
+
+func enabledWord(b bool) string {
+	if b {
+		return "enabled"
+	}
+	return "disabled"
+}
+
 // ---- MCP ----
 
 type mcpToolInput struct {

web/src/app/(main)/system/mcp/page.tsx

@@ -404,6 +404,19 @@ export default function MCPPage() {
                 <Badge variant="outline" className="uppercase">
                   {s.transport}
                 </Badge>
+                {s.last_connect_ok === false ? (
+                  <Badge variant="destructive" className="max-w-55 truncate font-normal" title={s.last_connect_err ?? "connect failed"}>
+                    down: {s.last_connect_err ? s.last_connect_err.slice(0, 60) : "connect failed"}
+                  </Badge>
+                ) : s.last_connect_ok === true ? (
+                  <Badge variant="secondary" className="font-normal">
+                    ok {s.last_connect_at ? new Date(s.last_connect_at).toLocaleTimeString() : ""}
+                  </Badge>
+                ) : (
+                  <Badge variant="outline" className="text-muted-foreground font-normal">
+                    not connected yet
+                  </Badge>
+                )}
                 <div className="ml-auto flex items-center gap-2" onClick={(e) => e.stopPropagation()}>
                   <Switch
                     checked={s.enabled}

web/src/lib/types.ts

@@ -1179,6 +1179,9 @@ export interface MCPServer {
   enabled: boolean;
   insecure?: boolean; // http: skip TLS cert verification (self-signed servers)
   timeout_seconds?: number; // http/sse: per-request timeout in seconds (default 120)
+  last_connect_at?: string | null; // last connect attempt (ISO time)
+  last_connect_ok?: boolean | null; // outcome of the last connect attempt
+  last_connect_err?: string | null; // failure reason when last_connect_ok is false
   tools?: string[]; // mcp_tools_cache (names only, for the count)
 }