Add MCP tool prompt support to system prompts

- Add tool_prompt to CoderPrompts class
- Modify fmt_system_prompt to include tool prompt when MCP tools are available
- This enables better handling of tool-based interactions when using MCP servers

aider/coders/base_coder.py

@@ -1155,6 +1155,9 @@ class Coder:
 
     def fmt_system_prompt(self, prompt):
         final_reminders = []
+        if self.mcp_tools and len(self.mcp_tools) > 0:
+            final_reminders.append(self.gpt_prompts.tool_prompt)
+
         if self.main_model.lazy:
             final_reminders.append(self.gpt_prompts.lazy_prompt)
         if self.main_model.overeager:

aider/coders/base_prompts.py

@@ -56,5 +56,16 @@ Do not edit these files!
     no_shell_cmd_prompt = ""
     no_shell_cmd_reminder = ""
 
+    tool_prompt = """Answer the user's request using the relevant tool(s), if they are available.
+Check that all the required parameters for each tool call are provided or can reasonably be
+inferred from context. IF there are no relevant tools or there are missing values for required
+parameters, ask the user to supply these values; otherwise proceed with the tool calls. If the
+user provides a specific value for a parameter (for example provided in quotes), make sure to
+use that value EXACTLY.
+DO NOT make up values for or ask about optional parameters. Carefully analyze descriptive terms in
+the request as they may indicate required parameter values that should be included even if not
+explicitly quoted.
+"""
+
     rename_with_shell = ""
     go_ahead_tip = ""