diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2bdc1228..d45652ae 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,12 @@
 
 ## [Unreleased]
 
+## [v0.51.574] — 2026-06-22 — Release UG (transparent-stream collapsed tool previews)
+
+### Fixed
+
+- **Collapsed tool rows in the Transparent Stream view show their one-line summary again.** A regression left collapsed tool cards showing only the bare tool name (`read_file`, `terminal`, `search_files`, `skill_view`) with no hint of what each call did — you had to expand every row. Each collapsed row now shows a quiet target-based summary (file path, command, search query, skill name) next to the tool name, without dumping the raw result into the row. Affects both live streaming and reloaded/old sessions (they share the render path). Fixes #4658.
+
 ## [v0.51.573] — 2026-06-22 — Release UF (reasoning request-storm fix)
 
 ### Fixed
diff --git a/static/ui.js b/static/ui.js
index cd306184..3d52866b 100644
--- a/static/ui.js
+++ b/static/ui.js
@@ -8216,6 +8216,31 @@ function _transparentToolStatus(tc, settled){
   if(tc&&tc.done===false) return settled?'Interrupted':'Running';
   return 'Completed';
 }
+// Quiet one-line summary for a collapsed transparent tool row (#4658).
+// The transparent view overrides the row name to the bare tool name
+// (_toolShortName, e.g. "read_file"/"terminal"), so — unlike the worklog view —
+// it has no action-label carrying the target, and buildToolCard's collapsed
+// preview is blanked for the common arg/shell case (the #4411 suppression that
+// assumes the name carries the target). That left transparent rows showing only
+// the bare tool name with no hint of what each call did. Rebuild a summary from
+// the call's TARGET (path/command/query/skill/...) — NOT the raw result JSON —
+// so it stays consistent with the "keep collapsed previews quiet" intent
+// (test_tool_card_preview_summary.py) while restoring "understand the call
+// without expanding it".
+function _transparentToolSummary(tc){
+  if(!tc||typeof tc!=='object') return '';
+  // Explicit progress text (e.g. subagent_progress) wins while still running.
+  const explicit=String(tc.preview||'').trim();
+  if(tc.done===false&&explicit) return _shortToolLabel(explicit,160);
+  // Target-based summary only (path/command/query/skill). Deliberately NO generic
+  // arg-preview fallback: a call with args but no real target (e.g. `terminal`
+  // with only {workdir} or an unknown tool with {mode:"dry-run"}) must yield an
+  // EMPTY collapsed preview rather than dumping a raw arg snippet — that keeps the
+  // collapsed row quiet and consistent with the no-args case (#4658 review).
+  const target=typeof _toolVisibleTargetLabel==='function'?_toolVisibleTargetLabel(tc,{limit:160}):'';
+  if(target) return target;
+  return '';
+}
 function _copyEventToClipboard(row){
   if(!row) return;
   const type=row.getAttribute('data-event-type');
@@ -8477,6 +8502,22 @@ function _decorateTransparentEventRow(row, opts){
       // also prefix the name with "Running:" — that's the same redundancy class
       // V6 removed from the detail body. (Trifecta r2 #4.)
       if(nameEl) nameEl.textContent=_toolShortName(name);
+      // #4658: restore the collapsed-row inline summary. buildToolCard emits a
+      // `.tool-card-preview` span but blanks its text for the common case, and
+      // the bare _toolShortName above drops the target the worklog view carries
+      // in its action-label name. Populate the preview from a quiet,
+      // target-based summary so each collapsed row says what it did without
+      // expanding. Idempotent across re-decoration (status updates re-run this).
+      const previewEl=header.querySelector('.tool-card-preview');
+      if(previewEl){
+        const summary=_transparentToolSummary(tc);
+        if(summary){
+          previewEl.textContent=summary;
+          previewEl.removeAttribute('hidden');
+        }else{
+          previewEl.textContent='';
+        }
+      }
       let statusEl=header.querySelector('.transparent-event-status');
       if(!statusEl){
         statusEl=document.createElement('span');
diff --git a/tests/test_issue4658_transparent_collapsed_preview.py b/tests/test_issue4658_transparent_collapsed_preview.py
new file mode 100644
index 00000000..c0aa224c
--- /dev/null
+++ b/tests/test_issue4658_transparent_collapsed_preview.py
@@ -0,0 +1,226 @@
+"""Regression test for issue #4658: collapsed tool-card rows in the
+transparent-stream view lost their inline summary/preview.
+
+Symptom: collapsed transparent tool rows showed only the bare tool name
+(`read_file`, `terminal`, `search_files`) with no hint of what the call did;
+expanding still worked. Caused by the interaction of two changes:
+  * 69072ac34 moved buildToolCard's collapsed preview to an arg summary and
+    #4411 (6951d10a) then blanked that preview for the common arg/shell case
+    (it assumes the row NAME carries the target — true for the worklog view's
+    action-label name), and
+  * the transparent view (_decorateTransparentEventRow) overrides the row name
+    back to the BARE tool name (_toolShortName), so it had neither the
+    target-carrying label nor a preview.
+
+Fix: _decorateTransparentEventRow now populates the `.tool-card-preview` span
+from a quiet, TARGET-based summary (_transparentToolSummary) — path/command/
+query/skill, never the raw result JSON — so collapsed rows are self-describing
+again while honoring the "keep collapsed previews quiet" intent
+(test_tool_card_preview_summary.py).
+
+This drives the ACTUAL functions from static/ui.js via node + jsdom-free DOM
+shims, and runs the same render path live streaming and persisted reload share
+(both go through _decorateTransparentEventRow(buildToolCard(tc))).
+"""
+import json
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+
+REPO_ROOT = Path(__file__).parent.parent.resolve()
+UI_JS_PATH = REPO_ROOT / "static" / "ui.js"
+
+NODE = shutil.which("node")
+pytestmark = pytest.mark.skipif(NODE is None, reason="node not on PATH")
+
+
+_DRIVER_SRC = r"""
+const fs = require('fs');
+const src = fs.readFileSync(process.argv[2], 'utf8');
+
+// ── Minimal DOM shims (enough for buildToolCard + _decorateTransparentEventRow)
+function makeEl(tag){
+  const el = {
+    tagName: (tag||'div').toUpperCase(),
+    _attrs: {}, _classes: new Set(), children: [], style: {},
+    dataset: {}, _html: '', textContent: '', parentNode: null,
+    firstChild: null,
+    classList: {
+      add(c){el._classes.add(c)}, remove(c){el._classes.delete(c)},
+      toggle(c,on){const w=on===undefined?!el._classes.has(c):!!on; if(w)el._classes.add(c); else el._classes.delete(c);},
+      contains(c){return el._classes.has(c)},
+    },
+    setAttribute(k,v){el._attrs[k]=String(v);}, getAttribute(k){return k in el._attrs?el._attrs[k]:null;},
+    removeAttribute(k){delete el._attrs[k];}, hasAttribute(k){return k in el._attrs;},
+    appendChild(c){c.parentNode=el; el.children.push(c); el.firstChild=el.children[0]; return c;},
+    insertBefore(c,ref){c.parentNode=el; const i=el.children.indexOf(ref); if(i<0)el.children.push(c); else el.children.splice(i,0,c); el.firstChild=el.children[0]; return c;},
+    insertAdjacentHTML(){/* detail body not needed for collapsed-preview assertions */},
+    closest(){return null}, focus(){},
+    get innerHTML(){return el._html;},
+    set innerHTML(v){
+      el._html=String(v);
+      // Parse just the spans we assert on out of the template buildToolCard emits.
+      el.children=[];
+      const mk=(cls,text)=>{const c=makeEl('span'); c._classes=new Set(cls.split(' ').filter(Boolean)); c.textContent=text; c.parentNode=el; el.children.push(c);};
+      const grab=(cls)=>{const re=new RegExp('<span class="'+cls.replace(/[-]/g,'\\-')+'">([\\s\\S]*?)<\\/span>'); const m=el._html.match(re); return m?m[1]:null;};
+      const nameLabel=grab('tool-card-name-label');
+      if(nameLabel!==null){ const nameSpan=makeEl('span'); nameSpan._classes=new Set(['tool-card-name']); nameSpan.textContent=nameLabel; nameSpan.parentNode=el; el.children.push(nameSpan); }
+      const preview=grab('tool-card-preview');
+      if(preview!==null) mk('tool-card-preview', preview);
+      const header=makeEl('div'); header._classes=new Set(['tool-card-header']);
+      // re-home the parsed spans under a header element so querySelector('.tool-card-header') works
+      header.children=el.children.slice(); header.children.forEach(c=>c.parentNode=header);
+      const card=makeEl('div'); card._classes=new Set(['tool-card']); card.appendChild(header);
+      el.children=[card]; el.firstChild=card;
+    },
+    querySelector(sel){ return el._find(sel, false)[0]||null; },
+    querySelectorAll(sel){ return el._find(sel, true); },
+    _find(sel, all){
+      const want=sel.split(',').map(s=>s.trim().replace(/^\./,''));
+      const out=[];
+      const walk=(node)=>{ for(const c of (node.children||[])){ if(want.some(w=>c._classes&&c._classes.has(w))) out.push(c); walk(c);} };
+      walk(el); return out;
+    },
+  };
+  return el;
+}
+
+global.document = { createElement: (t)=>makeEl(t), querySelectorAll:()=>[], querySelector:()=>null };
+global.window = {};
+global.CSS = { escape: s=>s };
+global.t = undefined;
+global.li = () => '<svg></svg>';
+global.esc = s => String(s==null?'':s).replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;');
+global.toolIcon = () => '<svg></svg>';
+global._snippetLooksLikeDiff = () => false;
+global._colorDiffLines = s => s;
+global._attachCopyButton = () => {};
+global._attachProgressBar = () => {};
+global._wireTransparentHeaderToggle = () => {};
+global._transparentToolDetailHtml = () => '<div class="tool-card-detail"></div>';
+// _toolDisclosureIdentity pulls in worklog hashing helpers irrelevant to the
+// collapsed-preview assertion; stub it (only feeds a data- attribute).
+global._toolDisclosureIdentity = () => '';
+
+function extractFunc(name){
+  const re=new RegExp('function\\s+'+name+'\\s*\\(');
+  const start=src.search(re); if(start<0) throw new Error(name+' not found');
+  let i=src.indexOf('{',start); let depth=1; i++;
+  while(depth>0&&i<src.length){ if(src[i]==='{')depth++; else if(src[i]==='}')depth--; i++; }
+  return src.slice(start,i);
+}
+// helpers buildToolCard / decorate depend on — eval'd at TOP LEVEL (a function
+// declaration eval'd inside a callback would be scoped to that callback and
+// lost, so collect all sources and eval them once here).
+var _FN_NAMES=[
+ '_toolDisplayName','_toolActionKind','_toolKindIcon','_toolPathBasename',
+ '_decodeToolLabelEntities','_redactToolTargetLabel','_shortToolLabel','_toolI18n',
+ '_toolTargetLabel','_toolVisibleTargetLabel','_toolCommandTitle','_toolQueryTitle',
+ '_toolActionLabelText','_toolArgPreviewValue','_toolArgPreviewKeyIsHidden',
+ '_formatToolArgPreview','_toolCardPreviewText','_toolCardAllowsDetail',
+ '_toolDetailLeadLabel','_toolDetailLeadText','_toolShortName','_transparentEventPreview',
+ '_transparentToolStatus','_transparentToolSummary',
+ '_isMemorySave','_isSkillUpdate','_tcAction',
+ 'buildToolCard','_decorateTransparentEventRow',
+];
+var _FN_SRC='';
+for(var _i=0;_i<_FN_NAMES.length;_i++){
+  try{ _FN_SRC+=extractFunc(_FN_NAMES[_i])+'\n'; }catch(e){ /* optional helper absent */ }
+}
+eval(_FN_SRC);
+
+function previewFor(tc){
+  const row=_decorateTransparentEventRow(buildToolCard(tc),{
+    type:'tool', name:tc.name, status:_transparentToolStatus(tc,true), toolCall:tc,
+  });
+  const card=row.querySelector('.tool-card');
+  const header=card?card.querySelector('.tool-card-header'):null;
+  const preview=header?header.querySelector('.tool-card-preview'):null;
+  const name=header?header.querySelector('.tool-card-name'):null;
+  return { preview: preview?preview.textContent:null, name: name?name.textContent:null };
+}
+
+const cases = JSON.parse(process.argv[3]);
+const out = {};
+for(const [key,tc] of Object.entries(cases)) out[key]=previewFor(tc);
+process.stdout.write(JSON.stringify(out));
+"""
+
+
+CASES = {
+    "read_file": {"name": "read_file", "args": {"path": "/home/x/api/config.py"}, "snippet": '{"content":"1|import os"}', "done": True},
+    "terminal": {"name": "terminal", "args": {"command": "git fetch origin --quiet"}, "snippet": "275 /opt/...", "done": True},
+    "search_files": {"name": "search_files", "args": {"pattern": "buildToolCard", "path": "/tmp"}, "snippet": '{"total_count": 0}', "done": True},
+    "skill_view": {"name": "skill_view", "args": {"name": "opencode-review-agents"}, "snippet": '{"success": true}', "done": True},
+    "no_args": {"name": "terminal", "args": {}, "done": True},
+    "args_no_target": {"name": "terminal", "args": {"workdir": "/tmp"}, "done": True},
+    "unknown_tool_args": {"name": "frobnicate", "args": {"mode": "dry-run"}, "done": True},
+}
+
+
+@pytest.fixture(scope="module")
+def results(tmp_path_factory):
+    driver = tmp_path_factory.mktemp("t4658") / "driver.js"
+    driver.write_text(_DRIVER_SRC, encoding="utf-8")
+    proc = subprocess.run(
+        [NODE, str(driver), str(UI_JS_PATH), json.dumps(CASES)],
+        capture_output=True, text=True, timeout=30,
+    )
+    if proc.returncode != 0:
+        raise RuntimeError(f"node driver failed: {proc.stderr}")
+    return json.loads(proc.stdout)
+
+
+def test_read_file_row_shows_file_target(results):
+    r = results["read_file"]
+    assert r["name"] == "read_file", f"transparent row keeps the bare tool name: {r}"
+    assert "config.py" in (r["preview"] or ""), (
+        f"collapsed read_file row must show the file target inline, not be blank: {r}"
+    )
+
+
+def test_terminal_row_shows_command(results):
+    r = results["terminal"]
+    assert r["preview"], f"collapsed terminal row must not be blank (the #4658 regression): {r}"
+    assert "git fetch" in r["preview"], f"terminal row should summarize the command: {r}"
+
+
+def test_search_row_shows_pattern_not_result_json(results):
+    r = results["search_files"]
+    assert r["preview"], f"collapsed search row must not be blank: {r}"
+    assert "buildToolCard" in r["preview"], f"search row should show the pattern/query: {r}"
+    # Honor the "keep collapsed previews quiet" contract — no raw result JSON.
+    assert "total_count" not in r["preview"], f"raw result JSON must stay in the detail body: {r}"
+
+
+def test_skill_row_shows_skill_name(results):
+    r = results["skill_view"]
+    assert "opencode-review-agents" in (r["preview"] or ""), f"skill row should name the skill: {r}"
+
+
+def test_no_args_row_does_not_invent_noise(results):
+    # With no target/args there is nothing useful to summarize; the preview
+    # should be empty rather than echoing a status word as a fake summary.
+    r = results["no_args"]
+    assert r["preview"] in ("", None), f"no-target row should have an empty preview, got: {r}"
+
+
+def test_args_but_no_target_row_has_empty_preview(results):
+    # A call with args but NO real target (e.g. terminal with only {workdir})
+    # must NOT dump a raw arg snippet into the collapsed preview — that would
+    # contradict the quiet/target-based intent and the no-args case (#4658 review).
+    r = results["args_no_target"]
+    assert r["preview"] in ("", None), (
+        f"args-but-no-target row must have an empty collapsed preview (no raw arg dump), got: {r}"
+    )
+
+
+def test_unknown_tool_with_args_has_empty_preview(results):
+    # An unknown tool whose args yield no target must also stay empty rather than
+    # echoing {mode:"dry-run"} as an invented summary.
+    r = results["unknown_tool_args"]
+    assert r["preview"] in ("", None), (
+        f"unknown-tool args-only row must have an empty collapsed preview, got: {r}"
+    )