diff --git a/vibn-agent-runner/dist/agent-session-runner.js b/vibn-agent-runner/dist/agent-session-runner.js
index 8b91ae15..b291e186 100644
--- a/vibn-agent-runner/dist/agent-session-runner.js
+++ b/vibn-agent-runner/dist/agent-session-runner.js
@@ -300,21 +300,30 @@ File: "${path.relative(opts.repoRoot ?? ctx.workspaceRoot, task.filePath)}" (lin
     const toolFingerprints = [];
     let ralphIteration = 0;
     function fingerprintToolCall(tc) {
-        if (tc.name === "shell_exec") {
-            const cmd = String(tc.args?.command ?? "").trim();
-            const verb = cmd
-                .split("&&")
-                .map((s) => s.trim())
-                .find((s) => !s.startsWith("cd "))
-                ?.split(/\s+/)[0] ?? "shell";
-            return `shell_exec:${verb}`;
+        const name = tc.name;
+        const args = tc.args ?? {};
+        if (name === "shell_exec") {
+            const cmd = String(args.command ?? "").trim();
+            const firstWord = cmd.split(/\s+/)[0] ?? "shell";
+            return `shell_exec:${firstWord}`;
         }
-        if (tc.name === "fs_write" ||
-            tc.name === "fs_edit" ||
-            tc.name === "fs_read") {
-            return `${tc.name}:${tc.args?.path}`;
+        // Determine target based on most common descriptive parameter keys
+        const target = args.path ??
+            args.pattern ??
+            args.command ??
+            args.commandId ??
+            args.appUuid ??
+            args.uuid ??
+            "";
+        if (target) {
+            return `${name}:${target}`;
         }
-        return `${tc.name}:${Object.values(tc.args ?? {})[0]}`;
+        // Filter out common metadata like projectId, and use first real argument
+        const keys = Object.keys(args).filter((k) => k !== "projectId");
+        if (keys.length > 0) {
+            return `${name}:${args[keys[0]]}`;
+        }
+        return `${name}:default`;
     }
     while (subTurn < SUB_MAX_TURNS) {
         if (opts.isStopped()) {
@@ -421,20 +430,23 @@ ${verification.error}
         for (const tc of resp.toolCalls) {
             toolFingerprints.push(fingerprintToolCall(tc));
         }
-        const window = toolFingerprints.slice(-6);
+        const window = toolFingerprints.slice(-12);
         const counts = new Map();
         for (const fp of window)
             counts.set(fp, (counts.get(fp) ?? 0) + 1);
         let maxRepeats = 0;
+        let repeatedCmd = "";
         for (const [fp, n] of counts.entries()) {
-            if (n > maxRepeats)
+            if (n > maxRepeats) {
                 maxRepeats = n;
+                repeatedCmd = fp;
+            }
         }
-        if (maxRepeats >= 4) {
+        if (maxRepeats >= 6) {
             await emit({
                 ts: now(),
                 type: "error",
-                text: `Loop detected in subtask execution, breaking loop.`,
+                text: `Loop detected in subtask execution (repeated "${repeatedCmd}" ${maxRepeats}x in last 12 calls), breaking loop.`,
             });
             return false;
         }
diff --git a/vibn-agent-runner/src/agent-session-runner.ts b/vibn-agent-runner/src/agent-session-runner.ts
index 4f8e145f..8030ecea 100644
--- a/vibn-agent-runner/src/agent-session-runner.ts
+++ b/vibn-agent-runner/src/agent-session-runner.ts
@@ -403,24 +403,35 @@ File: "${path.relative(opts.repoRoot ?? ctx.workspaceRoot, task.filePath)}" (lin
   let ralphIteration = 0;
 
   function fingerprintToolCall(tc: any) {
-    if (tc.name === "shell_exec") {
-      const cmd = String(tc.args?.command ?? "").trim();
-      const verb =
-        cmd
-          .split("&&")
-          .map((s) => s.trim())
-          .find((s) => !s.startsWith("cd "))
-          ?.split(/\s+/)[0] ?? "shell";
-      return `shell_exec:${verb}`;
+    const name = tc.name;
+    const args = tc.args ?? {};
+
+    if (name === "shell_exec") {
+      const cmd = String(args.command ?? "").trim();
+      const firstWord = cmd.split(/\s+/)[0] ?? "shell";
+      return `shell_exec:${firstWord}`;
     }
-    if (
-      tc.name === "fs_write" ||
-      tc.name === "fs_edit" ||
-      tc.name === "fs_read"
-    ) {
-      return `${tc.name}:${tc.args?.path}`;
+
+    // Determine target based on most common descriptive parameter keys
+    const target =
+      args.path ??
+      args.pattern ??
+      args.command ??
+      args.commandId ??
+      args.appUuid ??
+      args.uuid ??
+      "";
+    if (target) {
+      return `${name}:${target}`;
     }
-    return `${tc.name}:${Object.values(tc.args ?? {})[0]}`;
+
+    // Filter out common metadata like projectId, and use first real argument
+    const keys = Object.keys(args).filter((k) => k !== "projectId");
+    if (keys.length > 0) {
+      return `${name}:${args[keys[0]]}`;
+    }
+
+    return `${name}:default`;
   }
 
   while (subTurn < SUB_MAX_TURNS) {
@@ -536,20 +547,24 @@ ${verification.error}
     for (const tc of resp.toolCalls) {
       toolFingerprints.push(fingerprintToolCall(tc));
     }
-    const window = toolFingerprints.slice(-6);
+    const window = toolFingerprints.slice(-12);
     const counts = new Map<string, number>();
     for (const fp of window) counts.set(fp, (counts.get(fp) ?? 0) + 1);
 
     let maxRepeats = 0;
+    let repeatedCmd = "";
     for (const [fp, n] of counts.entries()) {
-      if (n > maxRepeats) maxRepeats = n;
+      if (n > maxRepeats) {
+        maxRepeats = n;
+        repeatedCmd = fp;
+      }
     }
 
-    if (maxRepeats >= 4) {
+    if (maxRepeats >= 6) {
       await emit({
         ts: now(),
         type: "error",
-        text: `Loop detected in subtask execution, breaking loop.`,
+        text: `Loop detected in subtask execution (repeated "${repeatedCmd}" ${maxRepeats}x in last 12 calls), breaking loop.`,
       });
       return false;
     }