Drain the change buffer, returning all accumulated changes since last drain.
AI agents call sdk_change_buffer_drain to retrieve information from UI Bridge MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves buffered changes without side effects. 'Drain' in this context means to consume and return the buffer contents, a read operation common in event-driven systems. There is no indication of data modification, deletion, code execution, or financial impact. The operation is non-destructive and idempotent (draining an empty buffer returns nothing).
From the tool's definition Tool name 'sdk_change_buffer_drain' and description 'Drain the change buffer, returning all accumulated changes since last drain' indicate a retrieval operation that reads accumulated state/changes without modifying or executing external operations.
Attacks that exploit this kind of access
Drain the change buffer, returning all accumulated changes since last drain. It is categorised as a Read tool in the UI Bridge MCP MCP Server, which means it retrieves data without modifying state.
Register the UI Bridge MCP server in PolicyLayer and add a rule for sdk_change_buffer_drain: 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 UI Bridge MCP. Nothing to install.
sdk_change_buffer_drain 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 sdk_change_buffer_drain 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 sdk_change_buffer_drain. 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.
sdk_change_buffer_drain is provided by the UI Bridge MCP server (qontinui/ui-bridge-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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