diff --git a/scripts/drivers/types/antigravity/template.md b/scripts/drivers/types/antigravity/template.md
index ec82af66..5659f822 100644
--- a/scripts/drivers/types/antigravity/template.md
+++ b/scripts/drivers/types/antigravity/template.md
@@ -5,6 +5,8 @@ description: Cross-agent messaging via SQLite. Send messages between Claude Code
 
 Agent messaging command. **IMPORTANT: Always use the provided scripts. NEVER directly read or edit config files, DB, or team data. There is NO register.sh — use join.sh to join a team.**
 
+**Shell requirement:** All agmsg scripts are Bash scripts. Always execute them via `bash`, never via PowerShell or cmd directly. If your default shell is not Bash (e.g. PowerShell on Windows), wrap every command with `bash -lc '...'`. Example: `bash -lc '~/.agents/skills/__SKILL_NAME__/scripts/send.sh myteam alice bob "hello"'`. Do NOT construct DB paths manually — the scripts handle path resolution internally. If you need to redirect storage, use `AGMSG_STORAGE_PATH` (the supported override).
+
 ## Identity
 
 If you already know your AGENT and TEAMS from a previous `$__SKILL_NAME__` call in this session, skip to **Execute** below.
diff --git a/scripts/drivers/types/claude-code/template.md b/scripts/drivers/types/claude-code/template.md
index e0c41547..23ab8517 100644
--- a/scripts/drivers/types/claude-code/template.md
+++ b/scripts/drivers/types/claude-code/template.md
@@ -4,6 +4,8 @@ description: Agent messaging — check inbox, send messages, view history
 
 Agent messaging command. **IMPORTANT: Always use the provided scripts. NEVER directly read or edit config files, DB, or team data. There is NO register.sh — use join.sh to join a team.**
 
+**Shell requirement:** All agmsg scripts are Bash scripts. Always execute them via `bash`, never via PowerShell or cmd directly. If your default shell is not Bash (e.g. PowerShell on Windows), wrap every command with `bash -lc '...'`. Example: `bash -lc '~/.agents/skills/__SKILL_NAME__/scripts/send.sh myteam alice bob "hello"'`. Do NOT construct DB paths manually — the scripts handle path resolution internally. If you need to redirect storage, use `AGMSG_STORAGE_PATH` (the supported override).
+
 ## Identity
 
 If you already know your AGENT and TEAMS from a previous `/__SKILL_NAME__` call in this session, skip to **Execute** below.
diff --git a/scripts/drivers/types/codex/template.md b/scripts/drivers/types/codex/template.md
index 8dcf1195..6335bd85 100644
--- a/scripts/drivers/types/codex/template.md
+++ b/scripts/drivers/types/codex/template.md
@@ -5,6 +5,8 @@ description: Cross-agent messaging via SQLite. Send messages between Claude Code
 
 Agent messaging command. **IMPORTANT: Always use the provided scripts. NEVER directly read or edit config files, DB, or team data. There is NO register.sh — use join.sh to join a team.**
 
+**Shell requirement:** All agmsg scripts are Bash scripts. Always execute them via `bash`, never via PowerShell or cmd directly. If your default shell is not Bash (e.g. PowerShell on Windows), wrap every command with `bash -lc '...'`. Example: `bash -lc '~/.agents/skills/__SKILL_NAME__/scripts/send.sh myteam alice bob "hello"'`. Do NOT construct DB paths manually — the scripts handle path resolution internally. If you need to redirect storage, use `AGMSG_STORAGE_PATH` (the supported override).
+
 ## Identity
 
 If you already know your AGENT and TEAMS from a previous `$__SKILL_NAME__` call in this session, skip to **Execute** below.
diff --git a/scripts/drivers/types/copilot/template.md b/scripts/drivers/types/copilot/template.md
index a5709643..3b0c6826 100644
--- a/scripts/drivers/types/copilot/template.md
+++ b/scripts/drivers/types/copilot/template.md
@@ -5,6 +5,8 @@ description: Cross-agent messaging via SQLite. Send messages between Claude Code
 
 Agent messaging command. **IMPORTANT: Always use the provided scripts. NEVER directly read or edit config files, DB, or team data. There is NO register.sh — use join.sh to join a team.**
 
+**Shell requirement:** All agmsg scripts are Bash scripts. Always execute them via `bash`, never via PowerShell or cmd directly. If your default shell is not Bash (e.g. PowerShell on Windows), wrap every command with `bash -lc '...'`. Example: `bash -lc '~/.agents/skills/__SKILL_NAME__/scripts/send.sh myteam alice bob "hello"'`. Do NOT construct DB paths manually — the scripts handle path resolution internally. If you need to redirect storage, use `AGMSG_STORAGE_PATH` (the supported override).
+
 ## Identity
 
 If you already know your AGENT and TEAMS from a previous `/__SKILL_NAME__` call in this session, skip to **Execute** below.
diff --git a/scripts/drivers/types/cursor/template.md b/scripts/drivers/types/cursor/template.md
index 59602189..bb1f15bf 100644
--- a/scripts/drivers/types/cursor/template.md
+++ b/scripts/drivers/types/cursor/template.md
@@ -5,6 +5,8 @@ description: Cross-agent messaging via SQLite. Send messages between Claude Code
 
 Agent messaging command. **IMPORTANT: Always use the provided scripts. NEVER directly read or edit config files, DB, or team data. There is NO register.sh — use join.sh to join a team.**
 
+**Shell requirement:** All agmsg scripts are Bash scripts. Always execute them via `bash`, never via PowerShell or cmd directly. If your default shell is not Bash (e.g. PowerShell on Windows), wrap every command with `bash -lc '...'`. Example: `bash -lc '~/.agents/skills/__SKILL_NAME__/scripts/send.sh myteam alice bob "hello"'`. Do NOT construct DB paths manually — the scripts handle path resolution internally. If you need to redirect storage, use `AGMSG_STORAGE_PATH` (the supported override).
+
 ## Identity
 
 If you already know your AGENT and TEAMS from a previous `$__SKILL_NAME__` call in this session, skip to **Execute** below.
diff --git a/scripts/drivers/types/gemini/template.md b/scripts/drivers/types/gemini/template.md
index 92488f94..0d532ff1 100644
--- a/scripts/drivers/types/gemini/template.md
+++ b/scripts/drivers/types/gemini/template.md
@@ -5,6 +5,8 @@ description: Cross-agent messaging via SQLite. Send messages between Claude Code
 
 Agent messaging command. **IMPORTANT: Always use the provided scripts. NEVER directly read or edit config files, DB, or team data. There is NO register.sh — use join.sh to join a team.**
 
+**Shell requirement:** All agmsg scripts are Bash scripts. Always execute them via `bash`, never via PowerShell or cmd directly. If your default shell is not Bash (e.g. PowerShell on Windows), wrap every command with `bash -lc '...'`. Example: `bash -lc '~/.agents/skills/__SKILL_NAME__/scripts/send.sh myteam alice bob "hello"'`. Do NOT construct DB paths manually — the scripts handle path resolution internally. If you need to redirect storage, use `AGMSG_STORAGE_PATH` (the supported override).
+
 ## Identity
 
 If you already know your AGENT and TEAMS from a previous `$__SKILL_NAME__` call in this session, skip to **Execute** below.
diff --git a/scripts/drivers/types/grok-build/template.md b/scripts/drivers/types/grok-build/template.md
index 75756d57..903b9fa8 100644
--- a/scripts/drivers/types/grok-build/template.md
+++ b/scripts/drivers/types/grok-build/template.md
@@ -5,6 +5,8 @@ description: Cross-agent messaging via SQLite. Send messages between Claude Code
 
 Agent messaging command. **IMPORTANT: Always use the provided scripts. NEVER directly read or edit config files, DB, or team data. There is NO register.sh — use join.sh to join a team.**
 
+**Shell requirement:** All agmsg scripts are Bash scripts. Always execute them via `bash`, never via PowerShell or cmd directly. If your default shell is not Bash (e.g. PowerShell on Windows), wrap every command with `bash -lc '...'`. Example: `bash -lc '~/.agents/skills/__SKILL_NAME__/scripts/send.sh myteam alice bob "hello"'`. Do NOT construct DB paths manually — the scripts handle path resolution internally. If you need to redirect storage, use `AGMSG_STORAGE_PATH` (the supported override).
+
 ## Identity
 
 If you already know your AGENT and TEAMS from a previous `/__SKILL_NAME__` call in this session, skip to **Execute** below.
diff --git a/scripts/drivers/types/hermes/template.md b/scripts/drivers/types/hermes/template.md
index 19a5b9c1..54506cd2 100644
--- a/scripts/drivers/types/hermes/template.md
+++ b/scripts/drivers/types/hermes/template.md
@@ -5,6 +5,8 @@ description: Cross-agent messaging via SQLite. Send messages between Claude Code
 
 Hermes Agent skill for agmsg cross-agent messaging. **IMPORTANT: Always use the provided scripts. NEVER directly read or edit config files, DB, or team data. There is NO register.sh — use join.sh to join a team.**
 
+**Shell requirement:** All agmsg scripts are Bash scripts. Always execute them via `bash`, never via PowerShell or cmd directly. If your default shell is not Bash (e.g. PowerShell on Windows), wrap every command with `bash -lc '...'`. Example: `bash -lc '~/.agents/skills/__SKILL_NAME__/scripts/send.sh myteam alice bob "hello"'`. Do NOT construct DB paths manually — the scripts handle path resolution internally. If you need to redirect storage, use `AGMSG_STORAGE_PATH` (the supported override).
+
 ## Identity
 
 If you already know your AGENT and TEAMS from a previous `/__SKILL_NAME__` use in this session, skip to **Execute** below.
diff --git a/scripts/drivers/types/opencode/template.md b/scripts/drivers/types/opencode/template.md
index d263bfdd..1b1f42dd 100644
--- a/scripts/drivers/types/opencode/template.md
+++ b/scripts/drivers/types/opencode/template.md
@@ -5,6 +5,8 @@ description: Cross-agent messaging via SQLite. Send messages between Claude Code
 
 Agent messaging command. **IMPORTANT: Always use the provided scripts. NEVER directly read or edit config files, DB, or team data. There is NO register.sh — use join.sh to join a team.**
 
+**Shell requirement:** All agmsg scripts are Bash scripts. Always execute them via `bash`, never via PowerShell or cmd directly. If your default shell is not Bash (e.g. PowerShell on Windows), wrap every command with `bash -lc '...'`. Example: `bash -lc '~/.agents/skills/__SKILL_NAME__/scripts/send.sh myteam alice bob "hello"'`. Do NOT construct DB paths manually — the scripts handle path resolution internally. If you need to redirect storage, use `AGMSG_STORAGE_PATH` (the supported override).
+
 ## Identity
 
 If you already know your AGENT and TEAMS from a previous `$__SKILL_NAME__` call in this session, skip to **Execute** below.