feat: strip ALL tools from intercepted requests by default

Tools are only needed by the Antigravity webview for tool-call UI.
Our proxy doesn't need them — the model generates text responses fine
without tool definitions. Stripping all 20 tools saves ~15KB per request.

src/mitm/modify.rs

@@ -7,21 +7,10 @@
 use serde_json::Value;
 use tracing::info;
 
-/// Tools to KEEP — essential coding tools. Everything else gets stripped.
+/// Whether to strip ALL tool definitions (default: true).
-const KEEP_TOOLS: &[&str] = &[
+/// The model generates responses fine without them — tools are only
-    "view_file",
+/// needed by the Antigravity webview, not by our proxy.
-    "write_to_file",
+const STRIP_ALL_TOOLS: bool = true;
-    "replace_file_content",
-    "multi_replace_file_content",
-    "run_command",
-    "command_status",
-    "send_command_input",
-    "grep_search",
-    "find_by_name",
-    "list_dir",
-    "view_file_outline",
-    "view_code_item",
-];
 
 /// System instruction sections to STRIP (matched by XML tag name).
 /// These are verbose instructional manuals that add tokens but don't
@@ -124,24 +113,17 @@ pub fn modify_request(body: &[u8]) -> Option<Vec<u8>> {
         }
     }
 
-    // ── 3. Strip non-essential tools ─────────────────────────────────────
+    // ── 3. Strip tool definitions ────────────────────────────────────────
-    if let Some(tools) = json
+    if STRIP_ALL_TOOLS {
-        .pointer_mut("/request/tools")
+        if let Some(tools) = json
-        .and_then(|v| v.as_array_mut())
+            .pointer_mut("/request/tools")
-    {
+            .and_then(|v| v.as_array_mut())
-        let before = tools.len();
+        {
-
+            let count = tools.len();
-        tools.retain(|tool| {
+            if count > 0 {
-            if let Some(name) = tool["functionDeclarations"][0]["name"].as_str() {
+                tools.clear();
-                KEEP_TOOLS.contains(&name)
+                changes.push(format!("strip all {count} tools"));
-            } else {
-                true // keep unknown structure
             }
-        });
-
-        let removed = before - tools.len();
-        if removed > 0 {
-            changes.push(format!("strip {removed}/{before} tools (keep {})", KEEP_TOOLS.len()));
         }
     }
 
@@ -255,7 +237,7 @@ mod tests {
     }
 
     #[test]
-    fn test_modify_strips_tools() {
+    fn test_modify_strips_all_tools() {
         let body = serde_json::json!({
             "project": "test",
             "requestId": "test/1",
@@ -265,7 +247,6 @@ mod tests {
                     {"functionDeclarations": [{"name": "view_file", "description": "view", "parameters": {}}]},
                     {"functionDeclarations": [{"name": "browser_subagent", "description": "browse", "parameters": {}}]},
                     {"functionDeclarations": [{"name": "grep_search", "description": "grep", "parameters": {}}]},
-                    {"functionDeclarations": [{"name": "generate_image", "description": "img", "parameters": {}}]},
                 ],
                 "generationConfig": {}
             },
@@ -276,17 +257,8 @@ mod tests {
         let modified = modify_request(&bytes).unwrap();
         let result: Value = serde_json::from_slice(&modified).unwrap();
 
-        let tool_names: Vec<&str> = result["request"]["tools"]
+        let tools = result["request"]["tools"].as_array().unwrap();
-            .as_array()
+        assert!(tools.is_empty(), "all tools should be stripped");
-            .unwrap()
-            .iter()
-            .map(|t| t["functionDeclarations"][0]["name"].as_str().unwrap())
-            .collect();
-
-        assert!(tool_names.contains(&"view_file"));
-        assert!(tool_names.contains(&"grep_search"));
-        assert!(!tool_names.contains(&"browser_subagent"));
-        assert!(!tool_names.contains(&"generate_image"));
     }
 
     #[test]