fix: Do not inject tools when models don't support them; detect this conflict before API calls happen

src/client/model.rs

@@ -177,6 +177,10 @@ impl Model {
         self.data.max_output_tokens
     }
 
+    pub fn supports_function_calling(&self) -> bool {
+        self.data.supports_function_calling
+    }
+
     pub fn no_stream(&self) -> bool {
         self.data.no_stream
     }

src/config/input.rs

@@ -239,12 +239,17 @@ impl Input {
         patch_messages(&mut messages, model);
         model.guard_max_input_tokens(&messages)?;
         let (temperature, top_p) = (self.role().temperature(), self.role().top_p());
-        let functions = self.config.read().select_functions(self.role());
-        if let Some(vec) = &functions {
-            for def in vec {
-                debug!("Function definition: {:?}", def.name);
+        let functions = if model.supports_function_calling() {
+            let fns = self.config.read().select_functions(self.role());
+            if let Some(vec) = &fns {
+                for def in vec {
+                    debug!("Function definition: {:?}", def.name);
+                }
             }
-        }
+            fns
+        } else {
+            None
+        };
         Ok(ChatCompletionsData {
             messages,
             temperature,

src/config/mod.rs

@@ -1842,6 +1842,12 @@ impl Config {
             bail!("Already in an agent, please run '.exit agent' first to exit the current agent.");
         }
         let agent = Agent::init(config, agent_name, abort_signal.clone()).await?;
+        if !agent.model().supports_function_calling() {
+            eprintln!(
+                "Warning: The model '{}' does not support function calling. Agent tools (including todo, spawning, and user interaction) will not be available.",
+                agent.model().id()
+            );
+        }
         let session = session_name.map(|v| v.to_string()).or_else(|| {
             if config.read().macro_flag {
                 None