Add a span (cmn_schedule_span) to a schedule that either includes or excludes a window of time. Use to model holidays, blackout periods, or extra coverage hours on top of a base cmn_schedule.
AI agents use snow_add_schedule_entry 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 creates new schedule entries in ServiceNow, which is a reversible data modification operation. It falls under Write rather than Execute because it directly modifies structured data (schedule spans) rather than executing arbitrary code or queries.
From the tool's definition Tool description states "Add a span (cmn_schedule_span) to a schedule", which is a create/add operation. The action modifies schedule data by inserting new time windows (holidays, blackout periods, coverage hours) into ServiceNow's scheduling system.
Attacks that exploit this kind of access
Add a span (cmn_schedule_span) to a schedule that either includes or excludes a window of time. Use to model holidays, blackout periods, or extra coverage hours on top of a base cmn_schedule. 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_add_schedule_entry: 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_add_schedule_entry 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_add_schedule_entry 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_add_schedule_entry. 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_add_schedule_entry 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_add_schedule_entry 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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