Create a text frame on a master spread
AI agents use create_master_text_frame to create or update resources in InDesign UXP MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your InDesign UXP MCP Server environment.
This tool creates new content (a text frame) on master spreads, which are foundational design templates in InDesign. This is a reversible modification (Write category). Severity is medium because: (1) master spreads affect all pages that use them, so mistakes propagate widely; (2) however, the action is not destructive—text frames can be deleted or modified afterward; (3) an agent could inadvertently clutter or…
From the tool's definition Tool name and description indicate it 'Create[s] a text frame on a master spread' — a direct modification operation that adds new content to a master design template.
Documented attack patterns abuse exactly the kind of access create_master_text_frame gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and InDesign UXP MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for create_master_text_frame:
{
"version": "1",
"default": "deny",
"tools": {
"create_master_text_frame": {
"limits": [
{
"counter": "create_master_text_frame_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}create_master_text_frame 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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Create a text frame on a master spread. It is categorised as a Write tool in the InDesign UXP MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the InDesign UXP MCP Server MCP server in PolicyLayer and add a rule for create_master_text_frame: 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 InDesign UXP MCP Server. Nothing to install.
create_master_text_frame 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 create_master_text_frame 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 create_master_text_frame. 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.
create_master_text_frame is provided by the InDesign UXP MCP Server MCP server (theloniuser/indesign-uxp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 135 InDesign UXP MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
135 InDesign UXP MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.