AI agents use snow_merge_objects to create or update resources in Serac — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Serac environment.
This tool modifies data structures by merging/overwriting object properties. It is reversible (the original objects can be reconstructed if needed, and this is a local operation without persistence). The shallow merge behavior and key overwriting make it a Write operation rather than Read.
From the tool's definition Tool description states 'Merge an array of objects left-to-right via spread (later keys win)' — modifies objects by overwriting keys. Described as 'Local operation' indicating no persistence side effects, but data transformation occurs.
Attacks that exploit this kind of access
Merge an array of objects left-to-right via spread (later keys win). Note: this is a shallow merge despite the name — nested objects are overwritten, not merged recursively. Local operation. It is categorised as a Write tool in the Serac MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Serac MCP server in PolicyLayer and add a rule for snow_merge_objects: 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 Serac. Nothing to install.
snow_merge_objects is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the snow_merge_objects 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 snow_merge_objects. 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.
snow_merge_objects is provided by the Serac MCP server (serac-labs/serac). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
snow_merge_objects is one line of Serac's registry record.
The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.
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