diff --git a/ProwlCLI/Commands/AgentsSignalCommand.swift b/ProwlCLI/Commands/AgentsSignalCommand.swift
index 642a3dea..293c8d70 100644
--- a/ProwlCLI/Commands/AgentsSignalCommand.swift
+++ b/ProwlCLI/Commands/AgentsSignalCommand.swift
@@ -22,7 +22,7 @@ struct AgentsSignalCommand: ParsableCommand {
   @Option(name: .customLong("session"), help: "Opaque agent session identifier.")
   var sessionID: String?
 
-  @Option(name: .long, help: "Short result or reason returned with the signal (maximum 4096 UTF-8 bytes).")
+  @Option(name: .long, help: "Short result or reason returned with the signal (maximum 32768 UTF-8 bytes).")
   var detail: String?
 
   @OptionGroup var options: GlobalOptions
diff --git a/ProwlCLIContracts/Resources/cli-output-schema.json b/ProwlCLIContracts/Resources/cli-output-schema.json
index 6063d514..5d2361fe 100644
--- a/ProwlCLIContracts/Resources/cli-output-schema.json
+++ b/ProwlCLIContracts/Resources/cli-output-schema.json
@@ -745,7 +745,7 @@
             "detail": {
               "type": "string",
               "minLength": 1,
-              "maxLength": 4096
+              "maxLength": 32768
             },
             "claimed_origin": {
               "type": "string",
diff --git a/ProwlCLITests/AgentsCommandParsingTests.swift b/ProwlCLITests/AgentsCommandParsingTests.swift
index e704ada8..fb4770ab 100644
--- a/ProwlCLITests/AgentsCommandParsingTests.swift
+++ b/ProwlCLITests/AgentsCommandParsingTests.swift
@@ -55,6 +55,17 @@ final class AgentsCommandParsingTests: XCTestCase {
     XCTAssertThrowsError(try AgentsSignalCommand.parse(["complete"]))
     XCTAssertThrowsError(try AgentsSignalCommand.parse(["turn-ended", "--progress", "1"]))
     XCTAssertThrowsError(try AgentsSignalCommand.parse(["progress", "--progress", "101"]))
-    XCTAssertThrowsError(try AgentsSignalCommand.parse(["needs-input", "--detail", String(repeating: "x", count: 4_097)]))
+    XCTAssertNoThrow(
+      try AgentsSignalCommand.parse(["needs-input", "--detail", String(repeating: "x", count: 32_768)])
+    )
+    XCTAssertNoThrow(
+      try AgentsSignalCommand.parse(["needs-input", "--detail", String(repeating: "界", count: 10_922)])
+    )
+    XCTAssertThrowsError(
+      try AgentsSignalCommand.parse(["needs-input", "--detail", String(repeating: "x", count: 32_769)])
+    )
+    XCTAssertThrowsError(
+      try AgentsSignalCommand.parse(["needs-input", "--detail", String(repeating: "界", count: 10_923)])
+    )
   }
 }
diff --git a/docs-ai/013-prowl-cli/contracts/agents-signal.md b/docs-ai/013-prowl-cli/contracts/agents-signal.md
index 73167d02..57205e9b 100644
--- a/docs-ai/013-prowl-cli/contracts/agents-signal.md
+++ b/docs-ai/013-prowl-cli/contracts/agents-signal.md
@@ -33,7 +33,7 @@ producer's business judgment authoritative. `--origin` is caller-authored metada
 cannot upgrade source/confidence or satisfy a future native-hook capability check.
 
 `--session` and `--origin` are non-empty, control-free UTF-8 up to 256 bytes. `--detail`
-is non-empty, control-free UTF-8 up to 4096 bytes. Detail is a short result or reason returned
+is non-empty, control-free UTF-8 up to 32768 bytes. Detail is a short result or reason returned
 with the signal; it is not logged and does not change confidence. Large results use
 `agents read`; workflow outputs use `workflow done -`.
 
diff --git a/docs-ai/013-prowl-cli/contracts/input.md b/docs-ai/013-prowl-cli/contracts/input.md
index 2b7fbba7..665d0ee6 100644
--- a/docs-ai/013-prowl-cli/contracts/input.md
+++ b/docs-ai/013-prowl-cli/contracts/input.md
@@ -68,7 +68,7 @@ prowl agents signal <turn-ended|needs-input|session-start|session-end|progress>
 ```
 
 `--progress` is valid only with `progress`; omitting it means indeterminate progress.
-Session/origin are at most 256 UTF-8 bytes and detail is at most 4096. All are non-empty
+Session/origin are at most 256 UTF-8 bytes and detail is at most 32768. All are non-empty
 and control-free when present. Parser and handler enforce the same shared validation.
 See [agents-signal.md](agents-signal.md).
 
diff --git a/docs-ai/064-agent-completion-signals/000-plan.md b/docs-ai/064-agent-completion-signals/000-plan.md
index 9b84f187..1ecc0ab5 100644
--- a/docs-ai/064-agent-completion-signals/000-plan.md
+++ b/docs-ai/064-agent-completion-signals/000-plan.md
@@ -232,6 +232,10 @@ opencode; partial for qodercli/qwen/amp; docs/bundle for the rest). Key conclusi
 
 ## Amendments
 
+- Updated 2026-08-23 before merge: owner raised bounded signal `--detail` from 4 KiB to
+  32 KiB (32768 UTF-8 bytes). The larger bound remains well below the 32 MiB socket frame and
+  macOS argument budget, accommodates useful completion summaries, and preserves the rule
+  that transcript/workflow-sized output uses its dedicated channels.
 - Updated 2026-08-22 before S1 implementation: owner review separated runtime `turn-ended`
   from S2's cooperative `dispatch-complete`; retained bounded `--detail`; made public origin
   claimed metadata only; required explicit overflow/resnapshot; and moved the complete
diff --git a/docs-ai/064-agent-completion-signals/001-action.md b/docs-ai/064-agent-completion-signals/001-action.md
index 5167c3fe..6983562a 100644
--- a/docs-ai/064-agent-completion-signals/001-action.md
+++ b/docs-ai/064-agent-completion-signals/001-action.md
@@ -20,7 +20,7 @@ S1 does not add `agents wait`, launch-scoped runtime hooks, workflow completion,
 - Continue the 064 path before the 063 workflow runner. `prowl workflow done` remains the only command that completes a workflow step; agent signals are observation/control-plane evidence.
 - Rename the runtime edge from ambiguous `turn-complete` to `turn-ended`. A runtime hook can prove that a turn ended, not that an assigned task completed.
 - Reserve `dispatch-complete` for S2's paired dispatch protocol. S2 must ship the entire path atomically: `create` returns a `dispatch_id`, the agent reports `dispatch-complete --detail`, a bounded in-memory receipt survives pane closure (but not app restart), and `agents wait --dispatch` consumes it without destructive read semantics.
-- Keep bounded `--detail` in S1 so a cooperative producer can attach a short result/reason without forcing another CLI command. Detail is caller-authored metadata, never logged, never raises confidence, and is not a replacement for large transcript/workflow output channels.
+- Keep bounded `--detail` in S1 so a cooperative producer can attach a short result/reason without forcing another CLI command. The owner raised its limit from 4 KiB to 32 KiB before merge: this remains small relative to the 32 MiB socket frame and 1 MiB macOS argument budget while accommodating useful completion summaries. Detail is caller-authored metadata, never logged, never raises confidence, and is not a replacement for large transcript/workflow output channels.
 - Public `--origin` is only a claimed origin. It cannot mark a channel as verified, raise confidence, or satisfy future hook self-checks. S3 may upgrade provenance only through a Prowl-configured launch-scoped capability; this is a correctness boundary, not a heavyweight security boundary.
 - Each observer has bounded buffering. State churn may be recovered by a newer snapshot. Signal/lifecycle loss is never silent: overflow terminates with an explicit internal error, and S2's waiter must re-subscribe/resnapshot before exposing a failure.
 - S1 signal state is in-memory and surface-scoped. S2 owns the separate bounded dispatch-receipt retention needed to survive surface closure.
@@ -82,7 +82,9 @@ app xcresult (2423 tests), and `make build-app`. An isolated custom-socket Debug
 passed `list`/`agents` and returned `SOURCE_REQUIRED` for an outside `agents signal`; 11
 focused tests re-verified real kernel peer-PID framing, app signal recording, and observer
 delivery. All final commands passed; only the documented concurrent-instance Ghostty UI
-limitation remains.
+limitation remains. A pre-merge owner follow-up then raised `--detail` to 32768 UTF-8
+bytes; exact ASCII and multibyte boundary tests, CLI integration, app tests, lint, and the
+Debug build were repeated for that amendment.
 
 ## Review record
 
diff --git a/docs-ai/064-agent-completion-signals/002-s1-work-note.md b/docs-ai/064-agent-completion-signals/002-s1-work-note.md
index c50f5663..acf94f33 100644
--- a/docs-ai/064-agent-completion-signals/002-s1-work-note.md
+++ b/docs-ai/064-agent-completion-signals/002-s1-work-note.md
@@ -67,3 +67,4 @@ ad-hoc results continue through `agents read` or a future `agents wait --include
 - 2026-08-23 — Adversarial review round 1 at `99f0baa9`: no P0/P1; accepted four P3 hardening/docs findings (publisher liveness invariant, reentrancy-safe subscriber mutation, S2 `--until exit` reconciliation, encode-failure contract).
 - 2026-08-23 — Adversarial review round 2 at `a63ba4a4`: no P0/P1; accepted stricter published-agent close-all/prune ordering coverage plus precise dead-surface revision/terminated-continuation semantics.
 - 2026-08-23 — Adversarial review round 3 at `f26eb780`: no P0/P1/P2, merge-ready. Final validation repeated `make check`, CLI smoke/integration (87), app xcresult (2423), Debug build, isolated custom-socket discovery/rejection, and 11 focused socket/app-observer tests.
+- 2026-08-23 — Owner follow-up raised `--detail` from 4 KiB to 32 KiB before merge. ASCII and multibyte exact-boundary tests went RED/GREEN; CLI smoke/integration (87), app xcresult (2423), `make check`, and Debug build passed. A 32768-byte argument crossed the real Debug Unix socket into the app, while 32769 bytes failed at CLI validation.
diff --git a/docs/components/cli.md b/docs/components/cli.md
index 9c73c58e..68637a29 100644
--- a/docs/components/cli.md
+++ b/docs/components/cli.md
@@ -241,7 +241,7 @@ Events are `turn-ended`, `needs-input`, `session-start`, `session-end`, and `pro
 `turn-ended` means one runtime interaction ended; it does not complete a workflow or prove
 an assigned task is done. `--progress` accepts 0–100 and is valid only for `progress`.
 Optional `--session` and claimed `--origin` are limited to 256 UTF-8 bytes; `--detail`
-carries a short result/reason up to 4096 bytes. Values must be non-empty and control-free.
+carries a short result/reason up to 32768 UTF-8 bytes. Values must be non-empty and control-free.
 
 The command accepts no target: Prowl attributes the kernel socket peer PID through process
 ancestry to a live pane. It never uses UI focus or `PROWL_PANE_ID`; external terminals,
diff --git a/supacode/CLIService/Shared/InputModels.swift b/supacode/CLIService/Shared/InputModels.swift
index 4ec4f2f1..b22160d1 100644
--- a/supacode/CLIService/Shared/InputModels.swift
+++ b/supacode/CLIService/Shared/InputModels.swift
@@ -41,7 +41,7 @@ public enum AgentSignalEvent: String, Codable, CaseIterable, Sendable {
 public struct AgentSignalInput: Codable, Sendable {
   public static let maximumSessionIDBytes = 256
   public static let maximumOriginBytes = 256
-  public static let maximumDetailBytes = 4 * 1_024
+  public static let maximumDetailBytes = 32 * 1_024
 
   public let event: AgentSignalEvent
   public let progress: Int?
diff --git a/supacodeTests/CLIAgentSignalCommandHandlerTests.swift b/supacodeTests/CLIAgentSignalCommandHandlerTests.swift
index d70efc13..3f885480 100644
--- a/supacodeTests/CLIAgentSignalCommandHandlerTests.swift
+++ b/supacodeTests/CLIAgentSignalCommandHandlerTests.swift
@@ -121,6 +121,12 @@ struct CLIAgentSignalCommandHandlerTests {
       },
       recordSignal: { _, _ in true }
     )
+    let maximumDetail = AgentSignalInput(
+      event: .needsInput,
+      detail: String(repeating: "x", count: 32_768)
+    )
+    #expect(maximumDetail.validationErrorMessage == nil)
+
     let invalidInputs = [
       AgentSignalInput(event: .turnEnded, progress: 1),
       AgentSignalInput(event: .progress, progress: -1),
@@ -128,7 +134,7 @@ struct CLIAgentSignalCommandHandlerTests {
       AgentSignalInput(event: .needsInput, sessionID: ""),
       AgentSignalInput(event: .needsInput, origin: "bad\norigin"),
       AgentSignalInput(event: .needsInput, detail: "bad\u{0}detail"),
-      AgentSignalInput(event: .needsInput, detail: String(repeating: "x", count: 4_097)),
+      AgentSignalInput(event: .needsInput, detail: String(repeating: "x", count: 32_769)),
     ]
 
     for input in invalidInputs {