docs: clarify Function creation and registration boundaries

python/python/lancedb/db.py

@@ -693,19 +693,20 @@ class DBConnection(EnforceOverrides):
         raise NotImplementedError("serialize is not supported for this connection type")
 
     def create_function(self, definition: UdfDefinition) -> FunctionVersion:
-        """Register a scalar Python UDF and wait for its immutable version.
+        """Build and register a scalar Python UDF, then return its version.
 
+        The server builds the OCI image and registers the completed artifact.
         This is the blocking counterpart of :meth:`create_function_async`.
         Local connections raise ``NotImplementedError``.
         """
         return self.create_function_async(definition).wait()
 
     def create_function_async(self, definition: UdfDefinition) -> Job[FunctionVersion]:
-        """Register a scalar Python UDF through the remote Function catalog.
+        """Submit a scalar Python UDF for building and registration.
 
-        Submission returns a typed job. The immutable Function version becomes
-        available only when :meth:`Job.wait` succeeds. Local connections raise
-        ``NotImplementedError``.
+        The server-side job builds the OCI image, then registers the completed
+        artifact. Waiting on the job returns the immutable Function version.
+        Local connections raise ``NotImplementedError``.
         """
         raise NotImplementedError(
             "Function catalog operations are not supported for this connection type"
@@ -2267,9 +2268,10 @@ class AsyncConnection(object):
     async def create_function_async(
         self, definition: UdfDefinition
     ) -> AsyncJob[FunctionVersion]:
-        """Register a scalar Python UDF through the remote Function catalog.
+        """Submit a scalar Python UDF for building and registration.
 
-        The returned typed job resolves to the immutable Function version.
+        The server-side job builds the OCI image, then registers the completed
+        artifact. Waiting on the job returns the immutable Function version.
         Local connections raise ``NotImplementedError``.
         """
         if not isinstance(definition, UdfDefinition):

rust/lancedb/src/connection.rs

@@ -581,10 +581,11 @@ impl Connection {
         )
     }
 
-    /// Register a Python callable as a new immutable Function version.
+    /// Build and register a Python callable as an immutable Function version.
     ///
-    /// Registration is remote-only and always asynchronous. Waiting on the
-    /// returned typed job yields the durable [`crate::function::FunctionVersion`].
+    /// The server-side job builds the OCI image, then registers the completed
+    /// artifact. Waiting on the returned typed job yields the durable
+    /// [`crate::function::FunctionVersion`]. Creation is remote-only.
     /// Local databases return [`Error::NotSupported`].
     pub async fn create_function_async(
         &self,

rust/lancedb/src/database.rs

@@ -294,7 +294,7 @@ pub trait Database:
     ///
     /// See [`CloneTableRequest`] for detailed documentation and examples.
     async fn clone_table(&self, request: CloneTableRequest) -> Result<Arc<dyn BaseTable>>;
-    /// Register an immutable Function version through the remote catalog.
+    /// Submit a Function creation job that builds an image and registers it.
     async fn create_function_async(
         &self,
         _request: crate::function::FunctionRegistrationRequest,