List available sources from the Unstructured API.
AI agents call list_sources to retrieve information from Unstructured API MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs a query/enumeration operation to retrieve information about available sources. It has no capability to modify, delete, execute, or cause financial impact. The read-only nature and absence of side effects places it squarely in the Read category with low severity, as listing sources poses minimal security risk.
From the tool's definition Tool name is 'list_sources' and description states 'List available sources from the Unstructured API.' The verb 'list' combined with the read-only operation of retrieving/enumerating sources indicates no data modification or side effects.
Documented attack patterns abuse exactly the kind of access list_sources gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Unstructured API MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for list_sources:
{
"version": "1",
"default": "deny",
"tools": {
"list_sources": {}
}
}list_sources is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
List available sources from the Unstructured API. It is categorised as a Read tool in the Unstructured API MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Unstructured API MCP Server MCP server in PolicyLayer and add a rule for list_sources: 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 Unstructured API MCP Server. Nothing to install.
list_sources 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 list_sources 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 list_sources. 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.
list_sources is provided by the Unstructured API MCP Server MCP server (unstructured-io/uns-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 12 Unstructured API MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
12 Unstructured API MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.