[dotnet-port-api] Add per-tool agent mode controls #1097

From 11b680cfda8c6a32a6c2c89b74f85ab946ef9bdd Mon Sep 17 00:00:00 2001
X-GH-AW-Base-Commit: 15e68364d23450bb00f1c846218038b2c1152ada
From: "github-actions[bot]" <github-actions[bot]@users.noreply.github.com>
Date: Fri, 18 Sep 2026 05:35:06 +0000
Subject: [PATCH] [dotnet-port-api] Add per-tool agent mode controls

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 agent/harness/agentmode/agentmode.go      | 148 ++++++++++++-----
 agent/harness/agentmode/agentmode_test.go | 193 ++++++++++++++++++++++
 docs/dotnet-go-sdk-feature-comparison.md  |   2 +-
 3 files changed, 301 insertions(+), 42 deletions(-)

diff --git a/agent/harness/agentmode/agentmode.go b/agent/harness/agentmode/agentmode.go
index 32e1f69..c107779 100644
--- a/agent/harness/agentmode/agentmode.go
+++ b/agent/harness/agentmode/agentmode.go
@@ -25,14 +25,17 @@ import (
 
 const stateKey = "agentModeState"
 
+const modeGetInstructions = "Use the mode_get tool to check your current operating mode.\n"
+
+const modeSetInstructions = "Use the mode_set tool to switch between modes as your work progresses. Only use mode_set if the user explicitly instructs/allows you to change modes.\n\n"
+
+const planModeTransition = "7. When approval is granted, always switch to execute mode (using the `mode_set` tool), and follow the steps for *Execute mode*."
+
 const defaultInstructions = `## Agent Mode
 
 - You can operate in different modes. Depending on the mode you are in, you will be required to follow different processes.
 
-Use the mode_get tool to check your current operating mode.
-Use the mode_set tool to switch between modes as your work progresses. Only use mode_set if the user explicitly instructs/allows you to change modes.
-
-You are currently operating in the {current_mode} mode.
+{mode_get_instructions}{mode_set_instructions}You are currently operating in the {current_mode} mode.
 
 ### Mandatory Mode based Workflow
 
@@ -64,6 +67,14 @@ type Config struct {
 	// Instructions overrid
... (truncated)