diff --git a/app/configuration/default.py b/app/configuration/default.py
index 7d13e6c..f9c8a72 100644
--- a/app/configuration/default.py
+++ b/app/configuration/default.py
@@ -1,10 +1,12 @@
 # Retriever parameters
 SEMANTIC_RETRIEVER_PATH = "../models/api_semantic_retrieval.joblib"
+SEMANTIC_TOP_K = 5
 LEXICAL_RETRIEVER_PATH = "../models/api_lexical_retrieval.joblib"
+LEXICAL_TOP_K = 5
 CROSS_ENCODER_PATH = "cross-encoder/ms-marco-MiniLM-L-6-v2"
 CROSS_ENCODER_THRESHOLD = 2.0
-CROSS_ENCODER_MIN_TOP_K = 1
-CROSS_ENCODER_MAX_TOP_K = 5
+CROSS_ENCODER_MIN_TOP_K = 5
+CROSS_ENCODER_MAX_TOP_K = 10
 
 # Device parameters
 DEVICE = "mps"
diff --git a/app/main.py b/app/main.py
index e07cc7d..f03ddbb 100644
--- a/app/main.py
+++ b/app/main.py
@@ -51,8 +51,8 @@ async def startup_event():
     cross_encoder = CrossEncoder(model_name=conf.CROSS_ENCODER_PATH, device=conf.DEVICE)
     api_retriever = RetrieverReranker(
         cross_encoder=cross_encoder,
-        semantic_retriever=api_semantic_retriever,
-        lexical_retriever=api_lexical_retriever,
+        semantic_retriever=api_semantic_retriever.set_params(top_k=conf.SEMANTIC_TOP_K),
+        lexical_retriever=api_lexical_retriever.set_params(top_k=conf.LEXICAL_TOP_K),
         threshold=conf.CROSS_ENCODER_THRESHOLD,
         min_top_k=conf.CROSS_ENCODER_MIN_TOP_K,
         max_top_k=conf.CROSS_ENCODER_MAX_TOP_K,
diff --git a/ragger_duck/prompt/_api.py b/ragger_duck/prompt/_api.py
index d75626b..33ea74c 100644
--- a/ragger_duck/prompt/_api.py
+++ b/ragger_duck/prompt/_api.py
@@ -46,12 +46,13 @@ def __call__(self, query, **prompt_kwargs):
         signature_retriever = inspect.signature(self.api_retriever.query)
         if "lexical_query" in signature_retriever.parameters:
             logger.info(
-                f"Retriever {self.api_retriever.__class__.__name} supports lexical"
+                f"Retriever {self.api_retriever.__class__.__name__} supports lexical"
                 " queries"
             )
             prompt = (
-                "[INST] Summarize the query provided by extracting keywords from it. "
-                "Only list the keywords only separated by a comma. \n"
+                "[INST] Rephrase the query to have correct wording in a context of "
+                "machine-learning. Make sure to have the right spelling. Finally, only "
+                "provide a list of keywords separated by commas.\n\n"
                 f"query: {query}[/INST]"
             )
 
@@ -81,7 +82,7 @@ def __call__(self, query, **prompt_kwargs):
             "machine-learning question.\n\n"
             "Answer to the query below using the additional provided content. "
             "The additional content is composed of the HTML link to the source and the "
-            "extracted text to be used.\n\n"
+            "extracted contextual information.\n\n"
             "Be succinct.\n\n"
             f"query: {query}\n\n"
             f"{context_query} [/INST]."