diff --git a/src/tool_bias.py b/src/tool_bias.py
index bb33e86..d0d8c57 100644
--- a/src/tool_bias.py
+++ b/src/tool_bias.py
@@ -39,13 +39,23 @@ class ToolBiasEngine:
   lines = ["### Tooling Strategy"]
   
   preferred = []
+  low_priority = []
   for cat_tools in preset.categories.values():
    for t in cat_tools:
-    if isinstance(t, Tool) and t.weight >= 4:
-     preferred.append(t.name)
+    if not isinstance(t, Tool): continue
+    if t.weight >= 5:
+     preferred.append(f"{t.name} [HIGH PRIORITY]")
+    elif t.weight == 4:
+     preferred.append(f"{t.name} [PREFERRED]")
+    elif t.weight == 2:
+     low_priority.append(f"{t.name} [NOT RECOMMENDED]")
+    elif t.weight <= 1:
+     low_priority.append(f"{t.name} [LOW PRIORITY]")
   
   if preferred:
    lines.append(f"Preferred tools: {', '.join(preferred)}.")
+  if low_priority:
+   lines.append(f"Low-priority tools: {', '.join(low_priority)}.")
   
   if global_bias.category_multipliers:
    lines.append("Category focus multipliers:")
diff --git a/tests/test_bias_efficacy.py b/tests/test_bias_efficacy.py
new file mode 100644
index 0000000..9710b86
--- /dev/null
+++ b/tests/test_bias_efficacy.py
@@ -0,0 +1,51 @@
+import pytest
+from src import ai_client
+from src.models import ToolPreset, Tool, BiasProfile
+from unittest.mock import MagicMock, patch
+
+def test_bias_efficacy_prompt_generation():
+ # Verify that the generated prompt contains the expected nudges and strategy
+ preset = ToolPreset(name="BiasTest", categories={
+  "General": [
+   Tool(name="list_directory", weight=5),
+   Tool(name="search_files", weight=1)
+  ]
+ })
+ bias = BiasProfile(name="Balanced", category_multipliers={"General": 1.0})
+ 
+ with patch("src.ai_client._active_tool_preset", preset):
+  with patch("src.ai_client._active_bias_profile", bias):
+   prompt = ai_client._get_combined_system_prompt()
+   
+   # Check strategy section
+   assert "Tooling Strategy" in prompt
+   assert "list_directory" in prompt
+   assert "PREFERRED" in prompt or "HIGH PRIORITY" in prompt
+   
+   # Check tool definitions nudging
+   with patch("src.ai_client._agent_tools", {"list_directory": True, "search_files": True}):
+    # Anthropic tools as an example
+    with patch("src.ai_client._CACHED_ANTHROPIC_TOOLS", None):
+     tools = ai_client._get_anthropic_tools()
+     
+     ls_tool = next(t for t in tools if t["name"] == "list_directory")
+     search_tool = next(t for t in tools if t["name"] == "search_files")
+     
+     assert "[HIGH PRIORITY]" in ls_tool["description"]
+     assert "[LOW PRIORITY]" in ls_tool["description"] or "[LOW PRIORITY]" in search_tool["description"]
+
+def test_bias_parameter_nudging():
+ preset = ToolPreset(name="ParamTest", categories={
+  "General": [
+   Tool(name="read_file", parameter_bias={"path": "CRITICAL"})
+  ]
+ })
+ 
+ with patch("src.ai_client._active_tool_preset", preset):
+  with patch("src.ai_client._agent_tools", {"read_file": True}):
+   with patch("src.ai_client._CACHED_ANTHROPIC_TOOLS", None):
+    tools = ai_client._get_anthropic_tools()
+    read_tool = next(t for t in tools if t["name"] == "read_file")
+    
+    path_param_desc = read_tool["input_schema"]["properties"]["path"]["description"]
+    assert "[CRITICAL]" in path_param_desc