diff --git a/features/consolidated_action.feature b/features/consolidated_action.feature
index fdb5ddb8d..ead59b0ea 100644
--- a/features/consolidated_action.feature
+++ b/features/consolidated_action.feature
@@ -700,6 +700,27 @@ Feature: Consolidated Action
     And the action schema error should mention "namespace/name"
 
 
+  Scenario: Uppercase namespace is rejected by ActionConfigSchema
+    Given an action YAML string with name "MyOrg/my-action"
+    When I validate the action schema expecting failure
+    Then the action schema validation should fail
+    And the action schema error should mention "namespace/name"
+
+
+  Scenario: Uppercase name part is rejected by ActionConfigSchema
+    Given an action YAML string with name "myorg/MyAction"
+    When I validate the action schema expecting failure
+    Then the action schema validation should fail
+    And the action schema error should mention "namespace/name"
+
+
+  Scenario: Fully uppercase namespaced name is rejected by ActionConfigSchema
+    Given an action YAML string with name "MyOrg/MyAction"
+    When I validate the action schema expecting failure
+    Then the action schema validation should fail
+    And the action schema error should mention "namespace/name"
+
+
   Scenario: Invalid argument type
     Given an action YAML string with an argument of type "array"
     When I validate the action schema expecting failure
diff --git a/features/skill_schema.feature b/features/skill_schema.feature
index 5704307c6..144dcf8c2 100644
--- a/features/skill_schema.feature
+++ b/features/skill_schema.feature
@@ -137,6 +137,36 @@ Feature: Skill YAML schema validation
     Then the skill schema validation should fail
     And the skill schema error should mention "namespace/name"
 
+  Scenario: Uppercase namespace is rejected by SkillConfigSchema
+    Given a skill YAML string with name "MyOrg/my-skill"
+    When I validate the skill schema expecting failure
+    Then the skill schema validation should fail
+    And the skill schema error should mention "namespace/name"
+
+  Scenario: Uppercase name part is rejected by SkillConfigSchema
+    Given a skill YAML string with name "myorg/MySkill"
+    When I validate the skill schema expecting failure
+    Then the skill schema validation should fail
+    And the skill schema error should mention "namespace/name"
+
+  Scenario: Fully uppercase namespaced name is rejected by SkillConfigSchema
+    Given a skill YAML string with name "MyOrg/MySkill"
+    When I validate the skill schema expecting failure
+    Then the skill schema validation should fail
+    And the skill schema error should mention "namespace/name"
+
+  Scenario: Uppercase tool reference name is rejected by SkillToolRefSchema
+    Given a skill YAML string with an invalid tool ref name "MyOrg/MyTool"
+    When I validate the skill schema expecting failure
+    Then the skill schema validation should fail
+    And the skill schema error should mention "namespace/name"
+
+  Scenario: Uppercase include name is rejected by SkillIncludeSchema
+    Given a skill YAML string with an invalid include name "MyOrg/MySkill"
+    When I validate the skill schema expecting failure
+    Then the skill schema validation should fail
+    And the skill schema error should mention "namespace/name"
+
   Scenario: Invalid tool reference name
     Given a skill YAML string with an invalid tool ref name "no-slash-tool"
     When I validate the skill schema expecting failure
diff --git a/src/cleveragents/action/schema.py b/src/cleveragents/action/schema.py
index be1a697ff..8ce054207 100644
--- a/src/cleveragents/action/schema.py
+++ b/src/cleveragents/action/schema.py
@@ -39,10 +39,8 @@ logger = logging.getLogger(__name__)
 # Constants
 # ────────────────────────────────────────────────────────────
 
-#: Pattern for ``<namespace>/<name>`` with hyphens, underscores, alphanum.
-NAMESPACED_NAME_RE = re.compile(
-    r"^[a-zA-Z0-9][a-zA-Z0-9_-]*/[a-zA-Z0-9][a-zA-Z0-9_-]*$"
-)
+#: Pattern for ``<namespace>/<name>`` with hyphens, underscores, lowercase alphanum.
+NAMESPACED_NAME_RE = re.compile(r"^[a-z0-9][a-z0-9_-]*/[a-z0-9][a-z0-9_-]*$")
 
 #: Pattern for ``${VAR}`` environment variable references.
 _ENV_VAR_RE = re.compile(r"\$\{([A-Za-z_][A-Za-z0-9_]*)\}")
diff --git a/src/cleveragents/skills/schema.py b/src/cleveragents/skills/schema.py
index ddd4a0556..25cfa722c 100644
--- a/src/cleveragents/skills/schema.py
+++ b/src/cleveragents/skills/schema.py
@@ -37,10 +37,8 @@ logger = logging.getLogger(__name__)
 # Constants
 # ────────────────────────────────────────────────────────────
 
-#: Pattern for ``<namespace>/<name>`` with hyphens, underscores, alphanum.
-NAMESPACED_NAME_RE = re.compile(
-    r"^[a-zA-Z0-9][a-zA-Z0-9_-]*/[a-zA-Z0-9][a-zA-Z0-9_-]*$"
-)
+#: Pattern for ``<namespace>/<name>`` with hyphens, underscores, lowercase alphanum.
+NAMESPACED_NAME_RE = re.compile(r"^[a-z0-9][a-z0-9_-]*/[a-z0-9][a-z0-9_-]*$")
 
 #: Pattern for ``${VAR}`` environment variable references.
 _ENV_VAR_RE = re.compile(r"\$\{([A-Za-z_][A-Za-z0-9_]*)\}")