docs(skills): clarify LocalDirLazySkillSource host paths

Author: MukundaKatta

src/agents/sandbox/capabilities/skills.py

@@ -205,8 +205,17 @@ async def load_skill(
         src_root = self._src_root(source_grants=source_grants)
         if src_root is None:
             raise SkillsConfigError(
-                message="lazy skill source directory is unavailable",
-                context={"skill_name": skill_name},
+                message=(
+                    "lazy skill source directory is unavailable; "
+                    "LocalDirLazySkillSource expects a host filesystem path, not a path "
+                    "inside the sandbox"
+                ),
+                context={
+                    "skill_name": skill_name,
+                    "configured_source_path": None
+                    if self.source.src is None
+                    else str(self.source.src),
+                },
             )
 
         matches = [

tests/sandbox/capabilities/test_skills_capability.py

@@ -623,9 +623,19 @@ async def test_load_skill_rejects_missing_lazy_source_directory(self, tmp_path:
             )
         )
 
-        with pytest.raises(SkillsConfigError):
+        with pytest.raises(SkillsConfigError) as exc_info:
             await capability.load_skill("missing-skill")
 
+        assert (
+            exc_info.value.message
+            == "lazy skill source directory is unavailable; "
+            "LocalDirLazySkillSource expects a host filesystem path, not a path inside the sandbox"
+        )
+        assert exc_info.value.context == {
+            "skill_name": "missing-skill",
+            "configured_source_path": str(tmp_path / "missing-skills"),
+        }
+
     @pytest.mark.asyncio
     async def test_load_skill_rejects_ambiguous_skill_name(self, tmp_path: Path) -> None:
         workspace_root = tmp_path / "workspace"