This error appears to suggest that you’re using the Stackdriver Basic Tier which allows ‘Logging agent only’ as per the documentation, section ‘Stackdriver account service tiers’.
I presume you would need the Premium Tier:
Basic Tier: Stackdriver VM agents Logging agent only
Premium Tier: Logging agent and Monitoring agent
The Basic Tier is free. It provides basic features, a moderate allotment of logs, and access to built-in metrics. If you try using metrics other than the built-in ones, you may get this error.
As per this documentation the Monitoring agent's metrics are only available with the Stackdriver Premium service tier.