review comments

Author: esoteric-ephemera

mp_api/client/core/utils.py

@@ -81,17 +81,11 @@ def validate_api_key(api_key: str | None = None) -> str:
 
         api_key = SETTINGS.get("PMG_MAPI_KEY")
 
-    if not api_key:
-        raise ValueError(
-            "Please obtain an API key from https://materialsproject.org/api "
-            "and export it as an environment variable `MP_API_KEY`."
-        )
-
-    if api_key and len(api_key) != 32:
+    if not api_key or (wrong_len := len(api_key) != 32):
+        addendum = " Valid API keys are 32 characters." if wrong_len else ""
         raise ValueError(
-            "Please use a new API key from https://materialsproject.org/api "
-            "Keys for the new API are 32 characters, whereas keys for the legacy "
-            "API are 16 characters."
+            "Please obtain a valid API key from https://materialsproject.org/api "
+            f"and export it as an environment variable `MP_API_KEY`.{addendum}"
         )
 
     return api_key

mp_api/mcp/mp_mcp.py

@@ -20,12 +20,12 @@ class MPMcp(BaseModel):
     @property
     def client(self) -> MPRester:
         # Always return JSON compliant output for MCP
-        kwargs = {
-            **(self.client_kwargs or {}),
-            "use_document_model": False,
-            "monty_decode": False,
-        }
         if not self._client:
+            kwargs = {
+                **(self.client_kwargs or {}),
+                "use_document_model": False,
+                "monty_decode": False,
+            }
             self._client = MPRester(**kwargs)
         return self._client