AI agents use update_block_slot to create or update resources in GoHighLevel MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your GoHighLevel MCP Server environment.
The tool updates (modifies) an existing resource reversibly. This is a Write operation—changes to blocked time slots can be edited again or restored. The moderate severity reflects that misuse could disrupt scheduling/calendar operations for users, but the impact is confined to time-slot configuration and doesn't involve financial transactions, code execution, or irreversible deletions.
From the tool's definition Tool name is 'update_block_slot' and description states 'Update an existing blocked time slot', indicating modification of calendar/scheduling data rather than deletion or creation.
Documented attack patterns abuse exactly the kind of access update_block_slot gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and GoHighLevel MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for update_block_slot:
{
"version": "1",
"default": "deny",
"tools": {
"update_block_slot": {
"limits": [
{
"counter": "update_block_slot_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}update_block_slot stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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Update an existing blocked time slot. It is categorised as a Write tool in the GoHighLevel MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the GoHighLevel MCP Server MCP server in PolicyLayer and add a rule for update_block_slot: 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 GoHighLevel MCP Server. Nothing to install.
update_block_slot 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 update_block_slot 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 update_block_slot. 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.
update_block_slot is provided by the GoHighLevel MCP Server MCP server (mastanley13/gohighlevel-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 255 GoHighLevel MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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255 GoHighLevel MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.