AI agents call img_optimize to retrieve information from Yaver without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
h | integer | — | |
q | integer | — | Quality 1..100 |
w | integer | — | |
fmt | string | — | |
src | string | Yes | |
root | string | — | Optional project root ID |
Parameters from the server's own tool schema.
Even though img_optimize only reads data, uncontrolled read access leaks sensitive information and racks up API costs — an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.
Attacks that exploit this kind of access
Return a URL that resizes + reencodes an image on demand. Output is disk-cached. It is categorised as a Read tool in the Yaver MCP Server, which means it retrieves data without modifying state.
img_optimize accepts 6 parameters: h, q, w, fmt, src, root. Required: src. The full parameter table on this page comes from the server's own tool schema.
Register the Yaver MCP server in PolicyLayer and add a rule for img_optimize: 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 Yaver. Nothing to install.
img_optimize is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the img_optimize 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 img_optimize. 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.
img_optimize is provided by the Yaver MCP server (yaver-cli). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.