feat(agents): advertise declared agent variables in agent__list_available

src/config/agent.rs

@@ -1258,7 +1258,7 @@ fn load_agent_description(name: &str) -> String {
     String::new()
 }
 
-fn load_agent_variables(name: &str) -> Vec<AgentVariable> {
+pub fn load_agent_variables(name: &str) -> Vec<AgentVariable> {
     if let Ok(config) = AgentConfig::load(&paths::agent_config_file(name)) {
         return config.variables;
     }

src/config/mod.rs

@@ -28,7 +28,7 @@ pub(crate) use self::agent::AgentConfig;
 pub(crate) use self::agent::default_max_agent_depth;
 pub use self::agent::{
     Agent, AgentVariable, AgentVariables, complete_agent_variables, list_agents,
-    list_agents_with_descriptions,
+    list_agents_with_descriptions, load_agent_variables,
 };
 #[allow(unused_imports)]
 pub use self::app_config::AppConfig;

src/config/prompts.rs

@@ -87,7 +87,7 @@ pub(in crate::config) const DEFAULT_SPAWN_INSTRUCTIONS: &str = indoc! {"
     | `agent__spawn` | Spawn a subagent in the background. Returns an `id` immediately. Optional `variables` (string map) sets the target agent's declared variables, overriding inherited values. |
     | `agent__check` | Non-blocking status probe: running or finished. Never returns/consumes the result — use `agent__collect`. |
     | `agent__collect` | Blocking wait: wait for an agent to finish, return its output. |
-    | `agent__list_available` | List all agent types you can spawn (name + description). Use this to discover specialists before calling `agent__spawn`. |
+    | `agent__list_available` | List all agent types you can spawn (name + description + declared variables). Use this to discover specialists and the `variables` they accept before calling `agent__spawn`. |
     | `agent__list_running` | List all subagents YOU have spawned, with their status. |
     | `agent__cancel` | Cancel a running agent by ID. |
     | `agent__task_create` | Create a task in the dependency-aware task queue. Optional `variables` (string map) is passed to the auto-dispatched agent. |