skia_extract_scene
Extract a lightweight Skia scene tree from the selected canvas.
This record as markdown: /tools/io-github-vmoranv-jshookmcp/skia-extract-scene.md
What skia_extract_scene does on Jshookmcp
AI agents call skia_extract_scene to retrieve information from Jshookmcp without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Why skia_extract_scene is rated Low
The tool retrieves and inspects the structure of a Skia scene (a graphics rendering framework component) from a canvas. This is a read-only operation that queries or accesses data without creating, modifying, executing code, or deleting anything. No side effects or external operations are triggered. Low severity due to limited blast radius—extracting scene tree data poses minimal risk even if misused by an AI agent.
From the tool's definition Tool name 'skia_extract_scene' and description 'Extract a lightweight Skia scene tree from the selected canvas' indicate data retrieval from a canvas object.
Attacks that exploit this kind of access
The rule that runs skia_extract_scene safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Jshookmcp, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For skia_extract_scene, this is the rule to start with:
skia_extract_scene is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Jshookmcp, apply this rule, and every skia_extract_scene call is checked against it from then on.
Questions about skia_extract_scene
Extract a lightweight Skia scene tree from the selected canvas. It is categorised as a Read tool in the Jshookmcp MCP Server, which means it retrieves data without modifying state.
Register the Jshook MCP server in PolicyLayer and add a rule for skia_extract_scene: 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 Jshookmcp. Nothing to install.
skia_extract_scene 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 skia_extract_scene 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 skia_extract_scene. 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.
skia_extract_scene is provided by the Jshook MCP server (@jshookmcp/jshook). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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