diff --git a/config.example.yaml b/config.example.yaml
index c55eb8a..01ee994 100644
--- a/config.example.yaml
+++ b/config.example.yaml
@@ -29,8 +29,7 @@ summary_prompt: 'This is a summary of the chat history as a recap: '
 # Visit https://github.com/sigoden/llm-functions for setup instructions
 function_calling: true           # Enables or disables function calling (Globally).
 mapping_tools:                   # Alias for a tool or toolset
-  # web_search: 'search_duckduckgo'
-  # code_interpreter: 'execute_py_code'
+  # fs: 'fs_cat,fs_ls,fs_mkdir,fs_rm,fs_write'
 use_tools: null                  # Which tools to use by default
 # Regex for seletecting dangerous functions
 # User confirmation is required when executing these functions
diff --git a/src/config/agent.rs b/src/config/agent.rs
index a6257ca..82f887c 100644
--- a/src/config/agent.rs
+++ b/src/config/agent.rs
@@ -148,12 +148,7 @@ impl RoleLike for Agent {
     }
 
     fn use_tools(&self) -> Option<String> {
-        let common_tools = &self.definition.common_tools;
-        if common_tools.is_empty() {
-            None
-        } else {
-            Some(common_tools.join(","))
-        }
+        self.config.use_tools.clone()
     }
 
     fn set_model(&mut self, model: &Model) {
@@ -169,7 +164,9 @@ impl RoleLike for Agent {
         self.config.top_p = value;
     }
 
-    fn set_use_tools(&mut self, _value: Option<String>) {}
+    fn set_use_tools(&mut self, value: Option<String>) {
+        self.config.use_tools = value;
+    }
 }
 
 #[derive(Debug, Clone, Default, Deserialize, Serialize)]
@@ -182,6 +179,8 @@ pub struct AgentConfig {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub top_p: Option<f64>,
     #[serde(skip_serializing_if = "Option::is_none")]
+    use_tools: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub dangerously_functions_filter: Option<String>,
 }
 
@@ -206,8 +205,6 @@ pub struct AgentDefinition {
     pub conversation_starters: Vec<String>,
     #[serde(default)]
     pub documents: Vec<String>,
-    #[serde(default)]
-    pub common_tools: Vec<String>,
 }
 
 impl AgentDefinition {
diff --git a/src/config/mod.rs b/src/config/mod.rs
index d2804ed..eeffc87 100644
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -555,9 +555,6 @@ impl Config {
                 self.function_calling = value;
             }
             "use_tools" => {
-                if self.agent.is_some() {
-                    bail!("This action cannot be performed within an agent.")
-                }
                 let value = parse_value(value)?;
                 self.set_use_tools(value);
             }
@@ -1059,15 +1056,14 @@ impl Config {
     pub fn select_functions(&self, model: &Model, role: &Role) -> Option<Vec<FunctionDeclaration>> {
         let mut functions = vec![];
         if self.function_calling {
-            let use_tools = role.use_tools();
-            let declaration_names: HashSet<String> = self
-                .functions
-                .declarations()
-                .iter()
-                .map(|v| v.name.to_string())
-                .collect();
-            if let Some(use_tools) = use_tools {
+            if let Some(use_tools) = role.use_tools() {
                 let mut tool_names: HashSet<String> = Default::default();
+                let declaration_names: HashSet<String> = self
+                    .functions
+                    .declarations()
+                    .iter()
+                    .map(|v| v.name.to_string())
+                    .collect();
                 for item in use_tools.split(',') {
                     let item = item.trim();
                     if item == "all" {
@@ -1096,15 +1092,31 @@ impl Config {
                         }
                     })
                     .collect();
-                if let Some(agent) = &self.agent {
-                    let agent_functions = agent.functions().declarations().to_vec();
-                    functions = [agent_functions, functions].concat();
-                }
-                if !model.supports_function_calling() {
-                    functions.clear();
-                    if *IS_STDOUT_TERMINAL {
-                        eprintln!("{}", warning_text("WARNING: This LLM or client does not support function calling, despite the context requiring it."));
-                    }
+            }
+
+            if let Some(agent) = &self.agent {
+                let mut agent_functions = agent.functions().declarations().to_vec();
+                let tool_names: HashSet<String> = agent_functions
+                    .iter()
+                    .filter_map(|v| {
+                        if v.agent {
+                            None
+                        } else {
+                            Some(v.name.to_string())
+                        }
+                    })
+                    .collect();
+                agent_functions.extend(
+                    functions
+                        .into_iter()
+                        .filter(|v| !tool_names.contains(&v.name)),
+                );
+                functions = agent_functions;
+            }
+            if !functions.is_empty() && !model.supports_function_calling() {
+                functions.clear();
+                if *IS_STDOUT_TERMINAL {
+                    eprintln!("{}", warning_text("WARNING: This LLM or client does not support function calling, despite the context requiring it."));
                 }
             }
         };
diff --git a/src/function.rs b/src/function.rs
index 739ef0c..0016405 100644
--- a/src/function.rs
+++ b/src/function.rs
@@ -71,6 +71,10 @@ impl Functions {
         Ok(Self { declarations })
     }
 
+    pub fn find(&self, name: &str) -> Option<&FunctionDeclaration> {
+        self.declarations.iter().find(|v| v.name == name)
+    }
+
     pub fn contains(&self, name: &str) -> bool {
         self.declarations.iter().any(|v| v.name == name)
     }
@@ -89,6 +93,8 @@ pub struct FunctionDeclaration {
     pub name: String,
     pub description: String,
     pub parameters: JsonSchema,
+    #[serde(skip_serializing, default)]
+    pub agent: bool,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -154,7 +160,7 @@ impl ToolCall {
         let is_dangerously = config.read().is_dangerously_function(&function_name);
         let (call_name, cmd_name, mut cmd_args) = match &config.read().agent {
             Some(agent) => {
-                if agent.functions().contains(&function_name) {
+                if let Some(true) = agent.functions().find(&function_name).map(|v| v.agent) {
                     (
                         format!("{}:{}", agent.name(), function_name),
                         agent.name().to_string(),