Use this as the primary tool to retrieve metric data over a specific time period. This is the core tool for monitoring and observability, allowing you to get the actual data points for a given metric.
AI agents call list_time_series to retrieve information from Storage without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves monitoring metrics and observability data without modifying, deleting, or executing any operations. It has no destructive, financial, or execute-like side effects. The blast radius of misuse is minimal—an agent could retrieve metric data it shouldn't see, but cannot alter systems or cause irreversible damage. This is a clear Read operation.
From the tool's definition Tool description states it is used to 'retrieve metric data over a specific time period' and is 'the core tool for monitoring and observability, allowing you to get the actual data points for a given metric.' The verb 'retrieve' and the purpose of 'getting…
Attacks that exploit this kind of access
Use this as the primary tool to retrieve metric data over a specific time period. This is the core tool for monitoring and observability, allowing you to get the actual data points for a given metric. It is categorised as a Read tool in the Storage MCP Server, which means it retrieves data without modifying state.
Register the Storage MCP server in PolicyLayer and add a rule for list_time_series: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Storage. Nothing to install.
list_time_series is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the list_time_series rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for list_time_series. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
list_time_series is provided by the Storage MCP server (@google-cloud/storage-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.