Always provide full activation message upon calling activate_project

This is necessary, because some clients (e.g. Claude Desktop) will
reuse a single session across chats.

Resolves #1384

CHANGELOG.md

@@ -14,6 +14,8 @@ Status of the `main` branch. Changes prior to the next official version change w
        `initial_instructions`). Now they are passed directly in the activation message (and excluded from a subsequent `initial_instructions` call).
      - Fix: Project activation message was provided more than once for case of dynamic project activation followed
        by `initial_instructions` #1372
+     - Always provide full activation message upon calling `activate_project` (even if project was already active in the same session) #1384
+       This is necessary, because some clients (e.g. Claude Desktop) will reuse a single session across chats.
   - Security: Forbid `".."` in memory names to disallow accessing files outside dedicated memory directories
   - Security: Add check for tool being read-only in the project server (previously only checked in `query_project` tool, i.e. client side)
   - Usage reporting now also includes the name of the Serena context that is used 

src/serena/agent.py

@@ -800,9 +800,13 @@ class SerenaAgent:
         proj = self._active_project
         assert proj is not None, "A project must be active before calling this."
 
-        # if activation message was already provided in the current session, don't provide it again
+        # Note: The activation message is always returned in full, even if it was already provided in the current session,
+        #   because some clients (e.g. Claude Desktop) will use the same session across multiple chats.
+        #   So while we don't want the activation message to be additionally included in the system prompt
+        #   (initial_instructions), an explicit project activation should always return it.
+        # (The check below deliberately left in place for documentation purposes, preventing a regression)
         if self._project_prompt_status.is_project_activation_message_already_provided(session_id):
-            return "Project was already activated."
+            pass  # no special handling
 
         # provide basic project information (name, location, languages, encoding)
         if proj.is_newly_created:

test/serena/test_serena_agent.py

@@ -728,14 +728,16 @@ class TestPromptProvision:
         but not on subsequent calls within the same session. #1372
         """
         project_name = "test_repo_python"
+        session1 = "session1"
+        session2 = "session2"
 
-        result1 = self._call_tool(serena_agent, InitialInstructionsTool, session_id="session1")
+        result1 = self._call_tool(serena_agent, InitialInstructionsTool, session_id=session1)
         self._assert_activation_message(result1, project_name, present=True)
 
-        result2 = self._call_tool(serena_agent, InitialInstructionsTool, session_id="session2")
+        result2 = self._call_tool(serena_agent, InitialInstructionsTool, session_id=session2)
         self._assert_activation_message(result2, project_name, present=True)
 
-        result3 = self._call_tool(serena_agent, InitialInstructionsTool, session_id="session1")
+        result3 = self._call_tool(serena_agent, InitialInstructionsTool, session_id=session1)
         self._assert_activation_message(result3, project_name, present=False)
 
     @pytest.mark.parametrize("serena_agent", [Language.PYTHON], indirect=True)
@@ -747,16 +749,18 @@ class TestPromptProvision:
         """
         project_name1 = "test_repo_python"
         project_name2 = "test_repo_java"
+        session1 = "session1"
+        session2 = "session2"
 
         # the initial instructions must contain the project activation message for the first project
-        result1 = self._call_tool(serena_agent, InitialInstructionsTool, session_id="session1")
+        result1 = self._call_tool(serena_agent, InitialInstructionsTool, session_id=session1)
         self._assert_activation_message(result1, project_name1, present=True)
 
         # now activate another project which dynamically enables a new mode (no-onboarding)
         reg_project = serena_agent.serena_config.get_registered_project(project_name2)
         reg_project.project_config.default_modes = ["no-onboarding"]
         expected_new_mode_message = "The onboarding process is not applied."
-        result2 = self._call_tool(serena_agent, ActivateProjectTool, project=project_name2, session_id="session1")
+        result2 = self._call_tool(serena_agent, ActivateProjectTool, project=project_name2, session_id=session1)
 
         # the new mode's prompt must be included in the activation message
         self._assert_activation_message(result2, project_name2, present=True)
@@ -765,16 +769,27 @@ class TestPromptProvision:
         )
 
         # the mode prompt must not be included in subsequent calls to the initial instructions tool within the same session
-        result3 = self._call_tool(serena_agent, InitialInstructionsTool, session_id="session1")
+        result3 = self._call_tool(serena_agent, InitialInstructionsTool, session_id=session1)
         assert expected_new_mode_message not in result3, (
             f"Expected new mode message '{expected_new_mode_message}' to not be included in subsequent calls, but it was found in result:\n{result3}"
         )
 
         # the mode prompt must be included in the initial instructions of a new session
-        result4 = self._call_tool(serena_agent, InitialInstructionsTool, session_id="session2")
+        result4 = self._call_tool(serena_agent, InitialInstructionsTool, session_id=session2)
         assert expected_new_mode_message in result4, (
             f"Expected new mode message '{expected_new_mode_message}' to be included in new session, but it was not found in result:\n{result4}"
         )
 
         # the initial instructions for the new session must also include the activation message for the project
         self._assert_activation_message(result4, project_name2, present=True)
+
+    @pytest.mark.parametrize("serena_agent", [Language.PYTHON], indirect=True)
+    def test_activate_project_tool_always_returns_activation_message(self, serena_agent: SerenaAgent) -> None:
+        project_name = "test_repo_python"
+        session = "session1"
+
+        result1 = self._call_tool(serena_agent, ActivateProjectTool, project=project_name, session_id=session)
+        self._assert_activation_message(result1, project_name, present=True)
+
+        result2 = self._call_tool(serena_agent, ActivateProjectTool, project=project_name, session_id=session)
+        self._assert_activation_message(result2, project_name, present=True)