local_ydb_add_dynamic_nodes
Add extra dynamic tenant nodes beyond the configured primary dynamic node, one at a time. Without confirm=true it returns container/port plans; with confirm=true it starts each node, verifies its IC port appears in viewer/json nodelist, and checks tenant metadata.
This record as markdown: /tools/local-ydb/local-ydb-add-dynamic-nodes.md
What local_ydb_add_dynamic_nodes does on Local Ydb
AI agents invoke local_ydb_add_dynamic_nodes to trigger actions in Local Ydb. 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 local_ydb_add_dynamic_nodes is rated High
The tool executes infrastructure changes by launching new dynamic tenant nodes in a local YDB deployment. While without confirm=true it is read-like (returning plans), the primary capability is starting nodes (Execute). The blast radius is high because misconfigured nodes can destabilize the cluster or expose unintended ports.
From the tool's definition 'with confirm=true it starts each node, verifies its IC port appears in viewer/json nodelist, and checks tenant metadata' — the tool triggers external operations by starting container nodes in a live YDB deployment
Attacks that exploit this kind of access
The rule that runs local_ydb_add_dynamic_nodes safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Local Ydb, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For local_ydb_add_dynamic_nodes, this is the rule to start with:
local_ydb_add_dynamic_nodes 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 Local Ydb, apply this rule, and every local_ydb_add_dynamic_nodes call is checked against it from then on.
Questions about local_ydb_add_dynamic_nodes
Add extra dynamic tenant nodes beyond the configured primary dynamic node, one at a time. Without confirm=true it returns container/port plans; with confirm=true it starts each node, verifies its IC port appears in viewer/json nodelist, and checks tenant metadata. It is categorised as a Execute tool in the Local Ydb MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Local Ydb MCP server in PolicyLayer and add a rule for local_ydb_add_dynamic_nodes: 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 Local Ydb. Nothing to install.
local_ydb_add_dynamic_nodes 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 local_ydb_add_dynamic_nodes 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 local_ydb_add_dynamic_nodes. 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.
local_ydb_add_dynamic_nodes is provided by the Local Ydb MCP server (@astandrik/local-ydb-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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