diff --git a/CHANGES.md b/CHANGES.md
index 1b72c3c45..180804ed8 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -2,11 +2,15 @@
 
 ## [Unreleased]
 
+### Added
+
+- added descriptive message to `types.search.str2bbox` length assert
+
 ### Fixed
 
-- Fix collection-search POST request model:
-  - Fix pydantic model to make sure class variables `_start_date` and `_end_date` not edited (ported from stac-pydantic)
-  - Fix bbox validation to allow anti-meridian crossing (ported from stac-pydantic)
+- fix collection-search POST request model:
+  - fix pydantic model to make sure class variables `_start_date` and `_end_date` not edited (ported from stac-pydantic)
+  - fix bbox validation to allow anti-meridian crossing (ported from stac-pydantic)
 
 ## [5.0.2] - 2025-01-30
 
diff --git a/stac_fastapi/types/stac_fastapi/types/search.py b/stac_fastapi/types/stac_fastapi/types/search.py
index 19f05caca..ea0a83818 100644
--- a/stac_fastapi/types/stac_fastapi/types/search.py
+++ b/stac_fastapi/types/stac_fastapi/types/search.py
@@ -35,7 +35,7 @@ def str2bbox(x: str) -> Optional[BBox]:
     """Convert string to BBox based on , delimiter."""
     if x:
         t = tuple(float(v) for v in str2list(x))
-        assert len(t) == 4
+        assert len(t) == 4, f"BBox '{x}' must have 4 values."
         return t
 
     return None