start_cluster
Start a terminated Databricks cluster with parameter: cluster_id (string, required)
This record as markdown: /tools/andresgarciasobrado91-databricks-mcp-server/start-cluster.md
What start_cluster does on Databricks MCP Server
AI agents invoke start_cluster to trigger actions in Databricks MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.
Why start_cluster is rated High
This is an Execute risk because it triggers an external operation (cluster startup) with side effects that depend on the provided cluster_id argument. It is not Read (no data retrieval), Write (not creating/modifying data reversibly), Destructive (cluster remains after startup), or Financial (no direct money movement).
From the tool's definition The tool description states 'Start a terminated Databricks cluster' - this initiates and triggers an external operation (cluster startup) whose infrastructure effects depend on the cluster_id argument.
Attacks that exploit this kind of access
The rule that runs start_cluster safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Databricks MCP Server, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For start_cluster, this is the rule to start with:
start_cluster stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Databricks MCP Server, apply this rule, and every start_cluster call is checked against it from then on.
Questions about start_cluster
Start a terminated Databricks cluster with parameter: cluster_id (string, required). It is categorised as a Execute tool in the Databricks MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Databricks MCP Server MCP server in PolicyLayer and add a rule for start_cluster: 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 Databricks MCP Server. Nothing to install.
start_cluster is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the start_cluster 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 start_cluster. 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.
start_cluster is provided by the Databricks MCP Server MCP server (andresgarciasobrado91/databricks-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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