fix(agent): improve ReAct parser and tool schemas for better LLM compatibility

- Fix ACTION_INPUT regex to properly capture multiline JSON responses
  - Changed from stopping at first newline to capturing all remaining text
  - Resolves parsing errors when LLM generates formatted JSON with line breaks

- Enhance tool schemas with detailed descriptions and parameter specifications
  - Add comprehensive Message schema for generate_text tool
  - Clarify distinction between resources/get (file read) and resources/list (directory listing)
  - Include clear usage guidance in tool descriptions

- Set default model to llama3.2:latest instead of invalid "ollama"

- Add parse error debugging to help troubleshoot LLM response issues

The agent infrastructure now correctly handles multiline tool arguments and
provides better guidance to LLMs through improved tool schemas. Remaining
errors are due to LLM quality (model making poor tool choices or generating
malformed responses), not infrastructure bugs.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

crates/owlen-core/src/tools.rs

@@ -0,0 +1,95 @@
+//! Tool module aggregating built‑in tool implementations.
+//!
+//! The crate originally declared `pub mod tools;` in `lib.rs` but the source
+//! directory only contained individual tool files without a `mod.rs`, causing the
+//! compiler to look for `tools.rs` and fail. Adding this module file makes the
+//! directory a proper Rust module and re‑exports the concrete tool types.
+
+pub mod code_exec;
+pub mod fs_tools;
+pub mod registry;
+pub mod web_search;
+pub mod web_search_detailed;
+
+use async_trait::async_trait;
+use serde_json::{json, Value};
+use std::collections::HashMap;
+use std::time::Duration;
+
+use crate::Result;
+
+/// Trait representing a tool that can be called via the MCP interface.
+#[async_trait]
+pub trait Tool: Send + Sync {
+    /// Unique name of the tool (used in the MCP protocol).
+    fn name(&self) -> &'static str;
+    /// Human‑readable description for documentation.
+    fn description(&self) -> &'static str;
+    /// JSON‑Schema describing the expected arguments.
+    fn schema(&self) -> Value;
+    /// Execute the tool with the provided arguments.
+    fn requires_network(&self) -> bool {
+        false
+    }
+    fn requires_filesystem(&self) -> Vec<String> {
+        Vec::new()
+    }
+    async fn execute(&self, args: Value) -> Result<ToolResult>;
+}
+
+/// Result returned by a tool execution.
+#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
+pub struct ToolResult {
+    /// Indicates whether the tool completed successfully.
+    pub success: bool,
+    /// Human‑readable status string – retained for compatibility.
+    pub status: String,
+    /// Arbitrary JSON payload describing the tool output.
+    pub output: Value,
+    /// Execution duration.
+    #[serde(skip_serializing_if = "Duration::is_zero", default)]
+    pub duration: Duration,
+    /// Optional key/value metadata for the tool invocation.
+    #[serde(default)]
+    pub metadata: HashMap<String, String>,
+}
+
+impl ToolResult {
+    pub fn success(output: Value) -> Self {
+        Self {
+            success: true,
+            status: "success".into(),
+            output,
+            duration: Duration::default(),
+            metadata: HashMap::new(),
+        }
+    }
+
+    pub fn error(msg: &str) -> Self {
+        Self {
+            success: false,
+            status: "error".into(),
+            output: json!({ "error": msg }),
+            duration: Duration::default(),
+            metadata: HashMap::new(),
+        }
+    }
+
+    pub fn cancelled(msg: &str) -> Self {
+        Self {
+            success: false,
+            status: "cancelled".into(),
+            output: json!({ "error": msg }),
+            duration: Duration::default(),
+            metadata: HashMap::new(),
+        }
+    }
+}
+
+// Re‑export the most commonly used types so they can be accessed as
+// `owlen_core::tools::CodeExecTool`, etc.
+pub use code_exec::CodeExecTool;
+pub use fs_tools::{ResourcesDeleteTool, ResourcesGetTool, ResourcesListTool, ResourcesWriteTool};
+pub use registry::ToolRegistry;
+pub use web_search::WebSearchTool;
+pub use web_search_detailed::WebSearchDetailedTool;