Updates an existing example data item owned by the authenticated user. Demonstrates ownership validation and partial updates.
AI agents use updateExampleData to create or update resources in MCP Authentication Demo — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MCP Authentication Demo environment.
This tool modifies existing data owned by the authenticated user. It is classified as Write rather than Read (retrieval only) or Destructive (irreversible deletion). The severity is medium because: (1) updates are reversible via subsequent corrections, (2) access is restricted to owned data via 'ownership validation', limiting blast radius, and (3) there is no mention of financial impact, code execution, or…
From the tool's definition Tool description states it 'Updates an existing example data item' - the verb 'Updates' and the context of modifying data owned by the authenticated user clearly indicates a write operation that creates or modifies data reversibly.
Documented attack patterns abuse exactly the kind of access updateExampleData gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MCP Authentication Demo, and nothing reaches the server without passing your rules. This is the rule we recommend for updateExampleData:
{
"version": "1",
"default": "deny",
"tools": {
"updateExampleData": {
"limits": [
{
"counter": "updateexampledata_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}updateExampleData 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.
Free to start. No card required.
Updates an existing example data item owned by the authenticated user. Demonstrates ownership validation and partial updates. It is categorised as a Write tool in the MCP Authentication Demo MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the MCP Authentication Demo MCP server in PolicyLayer and add a rule for updateExampleData: 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 MCP Authentication Demo. Nothing to install.
updateExampleData 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 updateExampleData 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 updateExampleData. 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.
updateExampleData is provided by the MCP Authentication Demo MCP server (workos/vercel-mcp-example). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from MCP Authentication Demo, 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.
5 MCP Authentication Demo tools catalogued and risk-classified — across an index of 43,000+ MCP servers.