diff --git a/changelog.d/timeline-tooluse.added.md b/changelog.d/timeline-tooluse.added.md
new file mode 100644
index 00000000..48d36e3d
--- /dev/null
+++ b/changelog.d/timeline-tooluse.added.md
@@ -0,0 +1 @@
+The Timeline window now shows which tools each Bot used, with how many times and how many of those failed, so a flaky tool or connector is visible where the run is drawn. Read-only, part of the existing `timeline/window` answer, tool names cleaned and capped.
diff --git a/docs/subsystems/timeline.md b/docs/subsystems/timeline.md
index d7987478..982620b9 100644
--- a/docs/subsystems/timeline.md
+++ b/docs/subsystems/timeline.md
@@ -26,7 +26,7 @@ Everything in `plugins/timeline/`: the recorder, the trace file, the read model
 | `plugins/timeline/src/adapter.js` | The only file that knows the `ctx.flybot` shape. |
 | `plugins/timeline/src/recorder.js` | Feed events to compact trace records; rebuilds every field from a strict alphabet. |
 | `plugins/timeline/src/store.js` | The trace: single writer, write-tmp + fsync + rename, capped segments. |
-| `plugins/timeline/src/window.js` | Pure read model: records to lanes, turns, tools, arrows, edges, utilization, the token spend per Bot (#357) and per-Bot outcomes and recent failures (#471). |
+| `plugins/timeline/src/window.js` | Pure read model: records to lanes, turns, tools, arrows, edges, utilization, the token spend per Bot (#357), per-Bot outcomes and recent failures (#471) and the tools each Bot used (#359). |
 | `plugins/timeline/client.js` | Browser entry (`@flybot/timeline`): the 2 s poller exposed as `ctx.flybot.timeline`, the geometry functions (`layoutSwimlanes`, `layoutMap`, `waitRows`, `utilizationRows`) and the panel (swimlanes, who waits on whom, utilization), opened from its `flybot.sidebar.section` row, the only entry (not in the + menu, #269). |
 | `plugins/timeline/src/sanitize.js` | The cleaners for ids, labels, codes, times, counts. |
 | `plugins/timeline/src/otel.js` | OTLP export: maps trace records to OpenTelemetry GenAI spans (`spansFrom`, `otlpPayload`) and a cursor exporter (`createExporter`). Off unless `config.exporter` is set. |
diff --git a/plugins/timeline/src/window.js b/plugins/timeline/src/window.js
index 154dbe28..5dd26f5b 100644
--- a/plugins/timeline/src/window.js
+++ b/plugins/timeline/src/window.js
@@ -260,6 +260,23 @@ export function buildWindow(records, { now = Date.now(), to, windowMs, bots = []
     return { lane: lane.id, calls: calls.length, input: sum('in'), output: sum('out'), cacheRead: sum('cr'), cacheWrite: sum('cw') }
   })
 
+  // ---- which tools each Bot used, and how often they failed (#357/#359 connectors)
+  const toolUse = lanes.filter(lane => lane.kind === 'bot').map((lane) => {
+    const counts = new Map()
+    for (const turn of turnList) {
+      if (turn.bot !== lane.id || turn.place === 'room') continue
+      for (const tool of toolsOf.get(turn.id) ?? []) {
+        const name = cleanLabel(tool.name, 60) || 'tool'
+        const entry = counts.get(name) ?? { name, calls: 0, failed: 0 }
+        entry.calls += 1
+        if (tool.ok === false) entry.failed += 1
+        counts.set(name, entry)
+      }
+    }
+    const tools = [...counts.values()].sort((a, b) => b.calls - a.calls || a.name.localeCompare(b.name)).slice(0, 20)
+    return { lane: lane.id, tools }
+  })
+
   // ---- communication map: directed edges, "A waits on B" from request -> reply latencies
   const edgeMap = new Map()
   for (const arrow of exchanges) {
@@ -293,6 +310,6 @@ export function buildWindow(records, { now = Date.now(), to, windowMs, bots = []
     coverage: { oldest: oldest ?? null, newest: last || null, complete: oldest !== undefined && oldest <= lo },
     trace: stats ?? null,
     truncated,
-    lanes, turns: shapedTurns, rounds, exchanges, utilization, edges, usage, outcomes, failures,
+    lanes, turns: shapedTurns, rounds, exchanges, utilization, edges, usage, outcomes, failures, toolUse,
   }
 }
diff --git a/plugins/timeline/test/window.test.js b/plugins/timeline/test/window.test.js
index a245f02f..bce8a8ae 100644
--- a/plugins/timeline/test/window.test.js
+++ b/plugins/timeline/test/window.test.js
@@ -274,3 +274,19 @@ test('outcomes: per-Bot turn endings and the recent failures (#357/#471)', () =>
   assert.deepEqual(win.outcomes.find(entry => entry.lane === 'b').aborted, 1)
   assert.deepEqual(win.failures.map(f => [f.id, f.bot, f.outcome, f.code]), [['b#1', 'b', 'aborted', undefined], ['a#2', 'a', 'error', 'RATE_LIMIT']])
 })
+
+test('toolUse: which tools a Bot used, and how often they failed (#357/#359)', () => {
+  const recs = [
+    { r: 'ts', t: at(1000), id: 'a#1', pl: 'chat', bot: 'a' },
+    { r: 'ks', t: at(1100), id: 'c1', tid: 'a#1', nm: 'web_search', bot: 'a' },
+    { r: 'ke', t: at(1200), id: 'c1', tid: 'a#1', ok: true },
+    { r: 'ks', t: at(1300), id: 'c2', tid: 'a#1', nm: 'mcp__github__search', bot: 'a' },
+    { r: 'ke', t: at(1400), id: 'c2', tid: 'a#1', ok: false },
+    { r: 'te', t: at(2000), id: 'a#1', o: 'completed' },
+  ]
+  const win = buildWindow(recs, { now: at(10_000), bots, rooms })
+  const a = win.toolUse.find(entry => entry.lane === 'a')
+  const byName = Object.fromEntries(a.tools.map(tool => [tool.name, [tool.calls, tool.failed]]))
+  assert.deepEqual(byName.web_search, [1, 0])
+  assert.deepEqual(byName['mcp__github__search'], [1, 1])
+})