fix(mcp): correct server param access and agent tool registration

- Use getattr() instead of .get() for accessing server.params attributes
- Fix tool registration logic to properly add tools to Agent

src/cai/repl/commands/mcp.py

@@ -116,11 +116,11 @@ class GlobalMCPUtil(MCPUtil):
         elif isinstance(server, MCPServerStdio):
             server_config["command"] = server.params.command
             server_config["args"] = server.params.args
-            server_config["env"] = server.params.get("env")
-            server_config["cwd"] = server.params.get("cwd")
-            server_config["encoding"] = server.params.get("encoding", "utf-8")
-            server_config["encoding_error_handler"] = server.params.get(
-                "encoding_error_handler", "strict"
+            server_config["env"] = getattr(server.params, "env")
+            server_config["cwd"] = getattr(server.params, "cwd")
+            server_config["encoding"] = getattr(server.params, "encoding", "utf-8")
+            server_config["encoding_error_handler"] = getattr(
+                server.params, "encoding_error_handler", "strict"
             )
 
         # Create a custom invoke function that creates a new connection each time
@@ -810,9 +810,9 @@ Example: `/mcp add burp 13`
 
         # Get the agent
         try:
-            agent = get_agent_by_name(agent_identifier)
+            agent = get_available_agents()[agent_identifier]
             agent_display_name = getattr(agent, "name", agent_identifier)
-        except ValueError:
+        except KeyError:
             # Try by index
             try:
                 agents = get_available_agents()