Execute a SPARQL query against any public HTTPS SPARQL endpoint. Args: - endpointUrl: URL of the target SPARQL endpoint (must be HTTPS) - query: SPARQL query to execute - injectPrefixes: Whether to inject schema.gov.it standard prefixes (default: false) Returns: - Compressed SPARQL results in the...
AI agents invoke query_external_endpoint to trigger actions in Schema Gov It MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
This tool executes arbitrary SPARQL queries against external endpoints specified by the caller. While SPARQL is primarily a query language, it can include UPDATE/DELETE operations depending on the endpoint, and the tool accepts arbitrary user-supplied queries and endpoint URLs.
From the tool's definition Execute a SPARQL query against any public HTTPS SPARQL endpoint
Documented attack patterns abuse exactly the kind of access query_external_endpoint gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Schema Gov It MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for query_external_endpoint:
{
"version": "1",
"default": "deny",
"tools": {
"query_external_endpoint": {
"limits": [
{
"counter": "query_external_endpoint_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}query_external_endpoint stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
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Execute a SPARQL query against any public HTTPS SPARQL endpoint. Args: - endpointUrl: URL of the target SPARQL endpoint (must be HTTPS) - query: SPARQL query to execute - injectPrefixes: Whether to inject schema.gov.it standard prefixes (default: false) Returns: - Compressed SPARQL results in the same format as internal tools Security: Only HTTPS endpoints are allowed. Requests timeout after 15 seconds. Examples: - Query DBpedia: endpointUrl=. It is categorised as a Execute tool in the Schema Gov It MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Schema Gov It MCP Server MCP server in PolicyLayer and add a rule for query_external_endpoint: 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 Schema Gov It MCP Server. Nothing to install.
query_external_endpoint is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the query_external_endpoint 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 query_external_endpoint. 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.
query_external_endpoint is provided by the Schema Gov It MCP Server MCP server (italia/dati-semantic-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Schema Gov It MCP Server, 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.
47 Schema Gov It MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.