fix(skills): scope 60-char description enforcement to the create path

The blanket MAX_DESCRIPTION_LENGTH=1024->60 change is narrowed:
create-time validation now rejects new skills whose description
exceeds SKILL_PROMPT_DESC_LIMIT (60) with actionable guidance, while
edit/patch paths stay permissive (warning via system_prompt_preview)
so existing over-limit skills remain maintainable. Runtime display
truncation in skills_tool is left at 1024 (display behavior is a
separate concern from authoring validation).

Boundary tests: 60 accepted, 61 rejected at create; edit/patch on
over-budget skills still succeed.

tests/tools/test_skill_manager_tool.py

@@ -275,14 +275,11 @@ class TestCreateSkill:
         assert f"Invalid category '{outside}'" in result["error"]
         assert not (outside / "my-skill" / "SKILL.md").exists()
 
-    def test_create_long_desc_includes_prompt_preview(self, tmp_path):
+    def test_create_long_desc_rejected(self, tmp_path):
         with _skill_dir(tmp_path):
             result = _create_skill("long-desc", LONG_DESC_CONTENT)
-        assert result["success"] is True
-        assert "system_prompt_preview" in result
-        assert "System prompt will show" in result["system_prompt_preview"]
-        fm, _ = parse_frontmatter(LONG_DESC_CONTENT)
-        assert extract_skill_description(fm) in result["system_prompt_preview"]
+        assert result["success"] is False
+        assert "system-prompt budget" in result["error"]
 
     def test_create_short_desc_no_prompt_preview(self, tmp_path):
         with _skill_dir(tmp_path):
@@ -290,7 +287,7 @@ class TestCreateSkill:
         assert result["success"] is True
         assert "system_prompt_preview" not in result
 
-    def test_create_boundary_at_limit_no_preview(self, tmp_path):
+    def test_create_boundary_at_limit_accepted_no_preview(self, tmp_path):
         desc = "U" * SKILL_PROMPT_DESC_LIMIT
         content = f"---\nname: boundary-at\ndescription: {desc}\n---\n\n# Boundary\n\nStep 1.\n"
         with _skill_dir(tmp_path):
@@ -298,13 +295,25 @@ class TestCreateSkill:
         assert result["success"] is True
         assert "system_prompt_preview" not in result
 
-    def test_create_boundary_over_limit_has_preview(self, tmp_path):
+    def test_create_boundary_over_limit_rejected(self, tmp_path):
         desc = "U" * (SKILL_PROMPT_DESC_LIMIT + 1)
         content = f"---\nname: boundary-over\ndescription: {desc}\n---\n\n# Boundary\n\nStep 1.\n"
         with _skill_dir(tmp_path):
             result = _create_skill("boundary-over", content)
+        assert result["success"] is False
+        assert "system-prompt budget" in result["error"]
+
+    def test_edit_long_desc_still_allowed_with_preview(self, tmp_path):
+        """Edit/patch paths stay permissive so existing over-limit skills
+        remain maintainable — they warn via system_prompt_preview instead."""
+        with _skill_dir(tmp_path):
+            _create_skill("my-skill", VALID_SKILL_CONTENT)
+            result = _edit_skill("my-skill", LONG_DESC_CONTENT)
         assert result["success"] is True
         assert "system_prompt_preview" in result
+        assert "System prompt will show" in result["system_prompt_preview"]
+        fm, _ = parse_frontmatter(LONG_DESC_CONTENT)
+        assert extract_skill_description(fm) in result["system_prompt_preview"]
 
 
 class TestEditSkill:

tools/skill_manager_tool.py

@@ -174,7 +174,7 @@ def _skills_dir() -> Path:
     return get_hermes_home() / "skills"
 
 MAX_NAME_LENGTH = 64
-MAX_DESCRIPTION_LENGTH = 60
+MAX_DESCRIPTION_LENGTH = 1024
 
 
 def _containing_skills_root(skill_path: Path) -> Path:
@@ -544,10 +544,16 @@ def _validate_category(category: Optional[str]) -> Optional[str]:
     return None
 
 
-def _validate_frontmatter(content: str) -> Optional[str]:
+def _validate_frontmatter(content: str, *, new_skill: bool = False) -> Optional[str]:
     """
     Validate that SKILL.md content has proper frontmatter with required fields.
     Returns error message or None if valid.
+
+    When ``new_skill`` is True (create path only), the description must also
+    fit the 60-char system-prompt budget (SKILL_PROMPT_DESC_LIMIT) so newly
+    authored skills never lose routing signal to index truncation. Edit and
+    patch paths deliberately skip this so existing over-limit skills remain
+    maintainable while their descriptions are cleaned up.
     """
     if not content.strip():
         return "Content cannot be empty."
@@ -576,8 +582,17 @@ def _validate_frontmatter(content: str) -> Optional[str]:
         return "Frontmatter must include 'name' field."
     if "description" not in parsed:
         return "Frontmatter must include 'description' field."
-    if len(str(parsed["description"])) > MAX_DESCRIPTION_LENGTH:
+    desc = str(parsed["description"])
+    if len(desc) > MAX_DESCRIPTION_LENGTH:
         return f"Description exceeds {MAX_DESCRIPTION_LENGTH} characters."
+    if new_skill and len(desc.strip().strip("'\"")) > SKILL_PROMPT_DESC_LIMIT:
+        return (
+            f"Description is {len(desc.strip())} chars — new skills must fit the "
+            f"{SKILL_PROMPT_DESC_LIMIT}-char system-prompt budget (one sentence, "
+            f"trigger first, ends with a period). The skill index truncates "
+            f"longer descriptions to {SKILL_PROMPT_DESC_LIMIT - 3} chars + '...', "
+            f"destroying the routing signal. Move detail into the skill body."
+        )
 
     body = content[end_match.end() + 3:].strip()
     if not body:
@@ -840,7 +855,7 @@ def _create_skill(name: str, content: str, category: str = None) -> Dict[str, An
         return {"success": False, "error": err}
 
     # Validate content
-    err = _validate_frontmatter(content)
+    err = _validate_frontmatter(content, new_skill=True)
     if err:
         return {"success": False, "error": err}
 

tools/skills_tool.py

@@ -160,7 +160,7 @@ def _skills_dir() -> Path:
 
 # Anthropic-recommended limits for progressive disclosure efficiency
 MAX_NAME_LENGTH = 64
-MAX_DESCRIPTION_LENGTH = 60
+MAX_DESCRIPTION_LENGTH = 1024
 
 # Platform identifiers for the 'platforms' frontmatter field.
 # Maps user-friendly names to sys.platform prefixes.