diff --git a/nanobot/skills/update-setup/SKILL.md b/nanobot/skills/update-setup/SKILL.md
index 104afcd5f..7e9d5cc60 100644
--- a/nanobot/skills/update-setup/SKILL.md
+++ b/nanobot/skills/update-setup/SKILL.md
@@ -13,21 +13,45 @@ Use `read_file` to check if `skills/update/SKILL.md` already exists in the works
 
 If it exists, use `ask_user` to ask: "An upgrade skill already exists. Reconfigure?" with options ["yes", "no"]. If no, stop here.
 
-## Step 2: Current Version
+## Step 2: Current Version and Install Clues
 
 Use `exec` to run `nanobot --version`. Tell the user the current version.
 
-## Step 3: Ask Questions
+Then collect install clues with `exec`. These commands are best-effort; if one fails,
+keep going and show the useful output:
 
-Use `ask_user` for the questions below, one question per call.
+```
+command -v nanobot || true
+python -m pip show nanobot-ai || true
+pipx list | sed -n '/nanobot-ai/,+3p' || true
+uv tool list | sed -n '/nanobot-ai/,+3p' || true
+```
+
+Summarize what you found in one short paragraph. Use the clues only to suggest a
+likely install method. Do not treat them as confirmation.
+
+## Step 3: Confirm Required Inputs
+
+CRITICAL: Do not write `skills/update/SKILL.md` until the install method is
+explicitly confirmed by the user. The install method must come from a user
+answer or confirmation, not from inference alone. If you cannot get a clear
+answer, stop and ask the user to rerun this setup when they know how nanobot was
+installed.
+
+Use `ask_user` for the questions below, one question per call. If `ask_user` is
+not available or cannot collect the answer, ask in normal chat and stop without
+writing the skill.
 
 **Question 1 — Install method:**
 
 ```
-question: "How did you install nanobot?"
-options: ["uv", "pipx", "pip", "source (git clone)"]
+question: "I found these install clues: <SUMMARY>. Which update method should this workspace use?"
+options: ["uv", "pipx", "pip", "source (git clone)", "not sure"]
 ```
 
+If the user selected `not sure`, explain the difference between the options and
+stop. Do not generate the upgrade skill.
+
 If the user selected `source (git clone)`, ask for the local checkout path:
 `question: "Where is your nanobot source checkout? Enter an absolute path or a path relative to this workspace:"`.
 
@@ -63,6 +87,18 @@ Determine the upgrade command from the install method:
 
 For source installs, include extras in the editable install command when selected. Quote the source checkout path if it contains spaces.
 
+Determine the preflight check from the install method:
+
+| Method | Preflight check |
+|--------|-----------------|
+| uv | `command -v uv` |
+| pipx | `command -v pipx` |
+| pip | `python -m pip --version` |
+| source | `test -d <SOURCE_CHECKOUT> && test -d <SOURCE_CHECKOUT>/.git && test -f <SOURCE_CHECKOUT>/pyproject.toml` |
+
+For source installs, quote the source checkout path in the preflight check if it
+contains spaces.
+
 Build the skill content. If proxy is configured, add `export http_proxy=URL` and `export https_proxy=URL` lines before the upgrade command.
 
 Use `write_file` to write `skills/update/SKILL.md` with this content:
@@ -76,9 +112,10 @@ description: "Upgrade nanobot to the latest version. Triggers: upgrade nanobot,
 # Update Nanobot
 
 1. (If proxy configured) Set proxy: `export http_proxy=URL && export https_proxy=URL`
-2. Use `exec` to run the upgrade command: <UPGRADE_COMMAND>
-3. Use `exec` to verify: `nanobot --version`
-4. Tell the user the new version. Say: "Run `/restart` to restart nanobot and apply the update. If `/restart` is unavailable in this channel, restart the nanobot process manually."
+2. Use `exec` to run the preflight check: <PREFLIGHT_CHECK>. If it fails, stop and tell the user to rerun `update-setup` because the saved install method no longer matches this environment.
+3. Use `exec` to run the upgrade command: <UPGRADE_COMMAND>
+4. Use `exec` to verify: `nanobot --version`
+5. Tell the user the new version. Say: "Run `/restart` to restart nanobot and apply the update. If `/restart` is unavailable in this channel, restart the nanobot process manually."
 ```
 
 ## Step 5: Confirm