Compress a single image from URL using TinyPNG API (only supports image files, not folders)
AI agents use compress_image_from_url to create or update resources in Image Tools — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Image Tools environment.
This tool sends an image to the TinyPNG API for compression and returns a modified (compressed) version. It creates/modifies image data via an external API. The operation is reversible in the sense that the original source URL is unchanged, but the output is a new compressed artifact. No deletion or execution of arbitrary code is involved, making Write the most appropriate category.
From the tool's definition Compress a single image from URL using TinyPNG API
Documented attack patterns abuse exactly the kind of access compress_image_from_url gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Image Tools, and nothing reaches the server without passing your rules. This is the rule we recommend for compress_image_from_url:
{
"version": "1",
"default": "deny",
"tools": {
"compress_image_from_url": {
"limits": [
{
"counter": "compress_image_from_url_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}compress_image_from_url 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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Compress a single image from URL using TinyPNG API (only supports image files, not folders). It is categorised as a Write tool in the Image Tools MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Image Tools MCP server in PolicyLayer and add a rule for compress_image_from_url: 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 Image Tools. Nothing to install.
compress_image_from_url 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 compress_image_from_url 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 compress_image_from_url. 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.
compress_image_from_url is provided by the Image Tools MCP server (kshern/image-tools-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Image Tools, 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.
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