AI agents call decode_plantuml to retrieve information from Plantuml without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool takes an encoded PlantUML string and reverses it to readable PlantUML source code. It is a read/transform operation with no external state changes, no data written, and no destructive actions possible. Blast radius is minimal as misuse can only produce incorrect decoded output.
From the tool's definition "Decode encoded PlantUML string back to PlantUML code" — purely a decoding/transformation operation with no side effects
Attacks that exploit this kind of access
Decode encoded PlantUML string back to PlantUML code. It is categorised as a Read tool in the Plantuml MCP Server, which means it retrieves data without modifying state.
Register the Plantuml MCP server in PolicyLayer and add a rule for decode_plantuml: 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 Plantuml. Nothing to install.
decode_plantuml 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 decode_plantuml 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 decode_plantuml. 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.
decode_plantuml is provided by the Plantuml MCP server (plantuml-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →