diff --git a/offline-backend-20260512/backend/packages/harness/deerflow/skills/storage/skill_storage.py b/offline-backend-20260512/backend/packages/harness/deerflow/skills/storage/skill_storage.py
index 33ef4b7b..40870aa7 100644
--- a/offline-backend-20260512/backend/packages/harness/deerflow/skills/storage/skill_storage.py
+++ b/offline-backend-20260512/backend/packages/harness/deerflow/skills/storage/skill_storage.py
@@ -12,7 +12,7 @@ from deerflow.skills.types import SKILL_MD_FILE, Skill, SkillCategory  # noqa: F
 
 logger = logging.getLogger(__name__)
 
-_SKILL_NAME_PATTERN = re.compile(r"^[a-z0-9]+(?:-[a-z0-9]+)*$")
+_SKILL_NAME_PATTERN = re.compile(r"^[a-z0-9]+(?:[_-][a-z0-9]+)*$")
 
 
 class SkillStorage(ABC):
@@ -36,7 +36,7 @@ class SkillStorage(ABC):
         """Validate and normalise a skill name; return the normalised form."""
         normalized = name.strip()
         if not _SKILL_NAME_PATTERN.fullmatch(normalized):
-            raise ValueError("Skill name must be hyphen-case using lowercase letters, digits, and hyphens only.")
+            raise ValueError("Skill name must use lowercase letters and digits separated by '-' or '_' only.")
         if len(normalized) > 64:
             raise ValueError("Skill name must be 64 characters or fewer.")
         return normalized
diff --git a/offline-backend-20260512/backend/packages/harness/deerflow/skills/validation.py b/offline-backend-20260512/backend/packages/harness/deerflow/skills/validation.py
index 8a2dd757..c95b67c0 100644
--- a/offline-backend-20260512/backend/packages/harness/deerflow/skills/validation.py
+++ b/offline-backend-20260512/backend/packages/harness/deerflow/skills/validation.py
@@ -65,11 +65,11 @@ def _validate_skill_frontmatter(skill_dir: Path) -> tuple[bool, str, str | None]
     if not name:
         return False, "Name cannot be empty", None
 
-    # Check naming convention (hyphen-case: lowercase with hyphens)
-    if not re.match(r"^[a-z0-9-]+$", name):
-        return False, f"Name '{name}' should be hyphen-case (lowercase letters, digits, and hyphens only)", None
-    if name.startswith("-") or name.endswith("-") or "--" in name:
-        return False, f"Name '{name}' cannot start/end with hyphen or contain consecutive hyphens", None
+    # Check naming convention (lowercase letters/digits separated by '-' or '_')
+    if not re.match(r"^[a-z0-9_-]+$", name):
+        return False, f"Name '{name}' should be lowercase letters, digits, hyphens or underscores only", None
+    if name[0] in "-_" or name[-1] in "-_" or re.search(r"[-_]{2,}", name):
+        return False, f"Name '{name}' cannot start/end with '-' or '_' or contain consecutive separators", None
     if len(name) > 64:
         return False, f"Name is too long ({len(name)} characters). Maximum is 64 characters.", None