diff --git a/runtime/prompt_prebuild.py b/runtime/prompt_prebuild.py
index abca7364..36c168ec 100644
--- a/runtime/prompt_prebuild.py
+++ b/runtime/prompt_prebuild.py
@@ -10,6 +10,7 @@ from oclaw.runtime.agent_context import build_role_system_context
 from oclaw.runtime.agents.specialists import discover_specialist_ids
 from oclaw.runtime.direct_loop import tool_wire_freeze_status, warm_tool_wire_cache
 from oclaw.runtime.skill_role_binding import SKILL_ROLE_BINDING_KEY
+from oclaw.runtime.skills import workspace_skills_layout_signature
 from oclaw.runtime.system_prompt import get_executor_prompt_static, warm_executor_prompt_cache
 from oclaw.runtime.tools.catalog import default_registry
 from oclaw.runtime.workspaces.experts import expert_workspace_signature_token, list_experts
@@ -84,6 +85,7 @@ def get_manager_prompt_prebuild(
         bool(memory_enabled),
         expert_workspace_signature_token(),
         _manager_settings_signature(store),
+        workspace_skills_layout_signature(),
     )
     with _MANAGER_PREBUILD_CACHE_LOCK:
         cached = _MANAGER_PREBUILD_CACHE.get(cache_key)
diff --git a/runtime/skills.py b/runtime/skills.py
index a0a68e53..cef2322f 100644
--- a/runtime/skills.py
+++ b/runtime/skills.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import hashlib
 import json
 import os
 import re
@@ -170,6 +171,38 @@ def discover_public_workspace_skill_names(skills_root: str | Path | None = None)
     return out
 
 
+def workspace_skills_layout_signature(skills_root: str | Path | None = None) -> str:
+    """Short hex signature that changes when any ``SKILL.md`` under the skills root moves or changes on disk.
+
+    Used to bust executor/manager prompt caches after install/uninstall/edit of workspace skills without
+    touching SQLite settings.
+    """
+    base = Path(skills_root).resolve() if skills_root else default_skills_root()
+    if not base.exists() or not base.is_dir():
+        return "0"
+    h = hashlib.sha256()
+    h.update(str(base).encode("utf-8", errors="ignore"))
+    h.update(b"\n")
+    try:
+        for skill_md in sorted(base.rglob("SKILL.md"), key=lambda p: str(p).lower()):
+            if not skill_md.is_file():
+                continue
+            try:
+                st = skill_md.stat()
+                rel = skill_md.relative_to(base).as_posix().lower()
+                h.update(rel.encode("utf-8", errors="ignore"))
+                h.update(str(int(st.st_mtime_ns)).encode("ascii", errors="ignore"))
+                h.update(b":")
+                h.update(str(int(st.st_size)).encode("ascii", errors="ignore"))
+                h.update(b"\n")
+            except OSError:
+                h.update(str(skill_md.resolve()).encode("utf-8", errors="ignore"))
+                h.update(b"\n?")
+    except OSError:
+        return "0:err"
+    return h.hexdigest()[:24]
+
+
 def _tool_origin(tool: "ToolSpec") -> str:
     nm = str(getattr(tool, "name", "") or "")
     if nm.startswith("mcp__"):
@@ -344,6 +377,7 @@ __all__ = [
     "build_skill_registry",
     "default_skills_root",
     "discover_workspace_skill_manifests",
+    "workspace_skills_layout_signature",
     "load_skill_manifest",
     "materialize_skills_from_tool_specs",
     "skill_runtime_diagnostics",
diff --git a/runtime/system_prompt.py b/runtime/system_prompt.py
index 54ea2892..3c353981 100644
--- a/runtime/system_prompt.py
+++ b/runtime/system_prompt.py
@@ -9,6 +9,7 @@ from oclaw.platform.config.paths import PROJECT_ROOT
 from oclaw.runtime.memory_stage import render_memory_context_block
 from oclaw.runtime.project_context_prompt import build_project_context_block
 from oclaw.runtime.skill_role_binding import SKILL_ROLE_BINDING_KEY
+from oclaw.runtime.skills import workspace_skills_layout_signature
 from oclaw.runtime.skills_prompt import build_skills_catalog_block
 from oclaw.runtime.skills_workspace_lane import (
     fs_safe_workspace_lane_segment,
@@ -205,6 +206,7 @@ def get_executor_prompt_static(
         str(skill_binding_role or "").strip().lower(),
         expert_workspace_signature_token(),
         _executor_prompt_settings_signature(store),
+        workspace_skills_layout_signature(),
         bool(tools is not None),
         int(bool(excl)),
         str(lane_seg or ""),
diff --git a/tests/test_oclaw_system_prompt.py b/tests/test_oclaw_system_prompt.py
index b72db624..ac5d7f40 100644
--- a/tests/test_oclaw_system_prompt.py
+++ b/tests/test_oclaw_system_prompt.py
@@ -4,6 +4,7 @@ from pathlib import Path
 
 import pytest
 
+from oclaw.runtime.skills import workspace_skills_layout_signature
 from oclaw.runtime.system_prompt import build_oclaw_executor_system_prompt
 from oclaw.runtime.types import OclawMemoryContext
 from oclaw.platform.persistence.sqlite_store import SqliteStore
@@ -129,6 +130,79 @@ def test_executor_static_prompt_cache_invalidates_on_settings_change(monkeypatch
     assert calls["n"] == 2
 
 
+def test_workspace_skills_layout_signature_changes_on_skill_md_edit(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
+    root = tmp_path / "skills_root_sig"
+    (root / "pkg").mkdir(parents=True)
+    f = root / "pkg" / "SKILL.md"
+    f.write_text("---\nname: x\ndescription: d\n---\n", encoding="utf-8")
+    monkeypatch.setenv("AIA_SKILLS_ROOT", str(root))
+    a = workspace_skills_layout_signature()
+    f.write_text("---\nname: x\ndescription: d\n---\n\nbody", encoding="utf-8")
+    b = workspace_skills_layout_signature()
+    assert a != b
+
+
+def test_executor_static_prompt_cache_invalidates_on_workspace_skills_layout_change(monkeypatch: pytest.MonkeyPatch) -> None:
+    from oclaw.runtime import system_prompt as sp
+
+    class DummyStore:
+        def get_setting(self, key: str) -> str:
+            _ = key
+            return ""
+
+    class DummyReg:
+        pass
+
+    calls = {"n": 0}
+    sig = {"v": "layout-a"}
+
+    def _skills_block(**kwargs) -> str:
+        _ = kwargs
+        calls["n"] += 1
+        return "skills-block"
+
+    monkeypatch.setattr(sp, "expert_workspace_signature_token", lambda: ("sig",))
+    monkeypatch.setattr(sp, "workspace_skills_layout_signature", lambda: sig["v"])
+    monkeypatch.setattr(sp, "build_project_context_block", lambda **kwargs: "")
+    monkeypatch.setattr(sp, "build_skills_catalog_block", _skills_block)
+    monkeypatch.setattr(
+        sp,
+        "render_runtime_prompt",
+        lambda prompt_id, variables, strict: f"{prompt_id}\n{variables.get('skills_catalog') or ''}",
+    )
+
+    store = DummyStore()
+    reg = DummyReg()
+    _ = sp.get_executor_prompt_static(
+        store=store,
+        tools=reg,  # type: ignore[arg-type]
+        base_url="",
+        base_system="base",
+        workspace_dir=None,
+        skill_binding_role="generalist",
+    )
+    _ = sp.get_executor_prompt_static(
+        store=store,
+        tools=reg,  # type: ignore[arg-type]
+        base_url="",
+        base_system="base",
+        workspace_dir=None,
+        skill_binding_role="generalist",
+    )
+    assert calls["n"] == 1
+
+    sig["v"] = "layout-b"
+    _ = sp.get_executor_prompt_static(
+        store=store,
+        tools=reg,  # type: ignore[arg-type]
+        base_url="",
+        base_system="base",
+        workspace_dir=None,
+        skill_binding_role="generalist",
+    )
+    assert calls["n"] == 2
+
+
 def test_executor_static_prompt_cache_invalidates_on_skill_role_binding_change(monkeypatch: pytest.MonkeyPatch) -> None:
     from oclaw.runtime import system_prompt as sp