Initializes asset upload and returns signed S3 upload URL.
AI agents use init_asset_upload to create or update resources in Storyblok MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Storyblok MCP Server environment.
This tool creates new assets in the Storyblok space by enabling uploads to S3 storage. While the upload itself is delegated to S3, the tool initiates and enables asset creation, making it a Write operation. It is not Destructive (no deletion), not Financial, and not Execute (it doesn't run arbitrary code—it generates a signed URL for a specific purpose).
From the tool's definition The tool 'init_asset_upload' returns a signed S3 upload URL, enabling the creation and storage of new assets. The description explicitly states it 'initializes asset upload', which is a write operation that creates new asset data in the system.
Documented attack patterns abuse exactly the kind of access init_asset_upload gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Storyblok MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for init_asset_upload:
{
"version": "1",
"default": "deny",
"tools": {
"init_asset_upload": {
"limits": [
{
"counter": "init_asset_upload_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}init_asset_upload 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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Initializes asset upload and returns signed S3 upload URL. It is categorised as a Write tool in the Storyblok MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Storyblok MCP Server MCP server in PolicyLayer and add a rule for init_asset_upload: 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 Storyblok MCP Server. Nothing to install.
init_asset_upload 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 init_asset_upload 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 init_asset_upload. 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.
init_asset_upload is provided by the Storyblok MCP Server MCP server (kiran1689/storyblok-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Storyblok MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
159 Storyblok MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.