refine pass-mgr usage guidance

skills/pass-mgr/SKILL.md

@@ -34,9 +34,11 @@ Always invoke pass_mgr through the `pcexec` tool. Do NOT run pass_mgr directly.
 ## Usage notes
 
 - Treat all outputs as sensitive. Do not echo secrets unless explicitly requested.
+- When the agent needs credentials to access a resource, first try `list` to see if a matching key already exists before asking the user.
 - Prefer `generate` when the user wants a new secret or password.
 - Use `set` to store both username and secret in one step.
 - Use `get-username` and `get-secret` for retrieval.
+- Storing can be explicit (user asks) or proactive after the agent successfully registers/creates an account.
 
 ## Examples (pcexec)