diff --git a/internal/config/schema_test.go b/internal/config/schema_test.go
new file mode 100644
index 0000000..17b1cfb
--- /dev/null
+++ b/internal/config/schema_test.go
@@ -0,0 +1,211 @@
+package config
+
+import (
+	"testing"
+
+	"gopkg.in/yaml.v3"
+)
+
+// TestAgentConfigParseMinimal verifies that a minimal config YAML (with only
+// required fields) parses into AgentConfig without error.
+func TestAgentConfigParseMinimal(t *testing.T) {
+	const minimalYAML = `
+agent:
+  id: test-bot
+  name: Test Bot
+  enabled: true
+matrix:
+  homeserver: "https://matrix.example.com"
+  user_id: "@test:matrix.example.com"
+llm:
+  primary:
+    provider: openai
+    model: gpt-4o
+`
+	var cfg AgentConfig
+	if err := yaml.Unmarshal([]byte(minimalYAML), &cfg); err != nil {
+		t.Fatalf("failed to parse minimal config: %v", err)
+	}
+	if cfg.Agent.ID != "test-bot" {
+		t.Errorf("expected agent.id=test-bot, got %q", cfg.Agent.ID)
+	}
+	if cfg.Matrix.Homeserver != "https://matrix.example.com" {
+		t.Errorf("expected homeserver, got %q", cfg.Matrix.Homeserver)
+	}
+	if cfg.LLM.Primary.Provider != "openai" {
+		t.Errorf("expected provider=openai, got %q", cfg.LLM.Primary.Provider)
+	}
+}
+
+// TestAgentConfigIgnoresRemovedSections verifies that YAML containing the
+// removed sections (agents, observability, resilience) still parses without
+// error. yaml.v3 silently ignores unknown keys.
+func TestAgentConfigIgnoresRemovedSections(t *testing.T) {
+	const yamlWithRemoved = `
+agent:
+  id: legacy-bot
+  name: Legacy Bot
+  enabled: true
+matrix:
+  homeserver: "https://matrix.example.com"
+  user_id: "@legacy:matrix.example.com"
+llm:
+  primary:
+    provider: openai
+    model: gpt-4o
+
+# These sections were removed from the schema but may still exist in old YAMLs.
+agents:
+  peers:
+    - id: other-bot
+      capabilities: [general]
+      room: "!abc:server.com"
+  delegation:
+    enabled: false
+  protocol:
+    format: json
+    channel: matrix
+
+observability:
+  logging:
+    level: info
+    format: json
+  metrics:
+    enabled: false
+  health:
+    enabled: true
+    port: 8080
+  tracing:
+    enabled: false
+
+resilience:
+  circuit_breaker:
+    failure_threshold: 5
+    timeout: 30s
+  retry:
+    max_attempts: 2
+    backoff: exponential
+  shutdown:
+    timeout: 10s
+  queue:
+    enabled: true
+    max_size: 100
+`
+	var cfg AgentConfig
+	if err := yaml.Unmarshal([]byte(yamlWithRemoved), &cfg); err != nil {
+		t.Fatalf("parsing config with removed sections should succeed, got: %v", err)
+	}
+	if cfg.Agent.ID != "legacy-bot" {
+		t.Errorf("expected agent.id=legacy-bot, got %q", cfg.Agent.ID)
+	}
+}
+
+// TestAgentConfigParseFull verifies that a config YAML with all active sections
+// parses correctly, including personality with communication.
+func TestAgentConfigParseFull(t *testing.T) {
+	const fullYAML = `
+agent:
+  id: full-bot
+  name: Full Bot
+  version: "1.0.0"
+  enabled: true
+  description: "A fully configured bot"
+  tags: [test, full]
+
+personality:
+  tone: friendly
+  verbosity: concise
+  language: es
+  role: "asistente general"
+  communication:
+    formality: semiformal
+    humor: subtle
+    personality: pragmatic
+    response_style: structured
+    quirks: ["usa analogias"]
+    avoid_topics: ["politica"]
+    catchphrases: ["interesante"]
+
+llm:
+  primary:
+    provider: openai
+    model: gpt-4o
+    api_key_env: OPENAI_API_KEY
+    max_tokens: 4096
+    temperature: 0.7
+  tool_use:
+    enabled: true
+    max_iterations: 5
+
+matrix:
+  homeserver: "https://matrix.example.com"
+  user_id: "@full:matrix.example.com"
+  access_token_env: MATRIX_TOKEN
+  threads:
+    enabled: true
+    auto_thread: false
+
+tools:
+  ssh:
+    enabled: false
+  http:
+    enabled: true
+    allowed_domains: ["api.example.com"]
+    timeout: 10s
+
+security:
+  sanitize:
+    enabled: true
+    mode: warn
+    min_severity: medium
+  tool_rate_limit:
+    enabled: true
+    max_calls_per_min: 10
+
+storage:
+  base_path: "/data/full-bot"
+
+memory:
+  enabled: true
+  window_size: 30
+
+skills:
+  enabled: true
+  path: "skills/"
+  categories: ["devops"]
+  timeout: 60s
+`
+	var cfg AgentConfig
+	if err := yaml.Unmarshal([]byte(fullYAML), &cfg); err != nil {
+		t.Fatalf("failed to parse full config: %v", err)
+	}
+
+	// Verify key fields
+	if cfg.Agent.ID != "full-bot" {
+		t.Errorf("agent.id: got %q", cfg.Agent.ID)
+	}
+	if cfg.Personality.Communication.Humor != "subtle" {
+		t.Errorf("personality.communication.humor: got %q", cfg.Personality.Communication.Humor)
+	}
+	if len(cfg.Personality.Communication.Quirks) != 1 {
+		t.Errorf("personality.communication.quirks: expected 1, got %d", len(cfg.Personality.Communication.Quirks))
+	}
+	if !cfg.LLM.ToolUse.Enabled {
+		t.Error("llm.tool_use.enabled should be true")
+	}
+	if !cfg.Tools.HTTP.Enabled {
+		t.Error("tools.http.enabled should be true")
+	}
+	if cfg.Storage.BasePath != "/data/full-bot" {
+		t.Errorf("storage.base_path: got %q", cfg.Storage.BasePath)
+	}
+	if !cfg.Memory.Enabled {
+		t.Error("memory.enabled should be true")
+	}
+	if !cfg.Skills.Enabled {
+		t.Error("skills.enabled should be true")
+	}
+	if !cfg.Security.Sanitize.Enabled {
+		t.Error("security.sanitize.enabled should be true")
+	}
+}