diff --git a/docs/guides/shacl-validation.md b/docs/guides/shacl-validation.md
index 8ee40f7e..df81df04 100644
--- a/docs/guides/shacl-validation.md
+++ b/docs/guides/shacl-validation.md
@@ -707,6 +707,22 @@ report_dict = report.to_dict()
 
 ---
 
+## Resource limits
+
+Live SHACL validation in the Explorer enforces four resource limits, all configurable
+through environment variables. When a limit trips, the error message names the
+variable that controls it.
+
+| Environment variable | Default | What it bounds |
+| --- | --- | --- |
+| `SEMANTICA_MAX_SHACL_TURTLE_BYTES` | `262144` (256 KB) | Size of the submitted SHACL Turtle |
+| `SEMANTICA_MAX_SHACL_TRIPLES` | `1000` | Triple count of the parsed shapes graph |
+| `SEMANTICA_MAX_SHACL_TIMEOUT` | `15.0` | Validation timeout in seconds |
+| `SEMANTICA_MAX_SHACL_CONCURRENCY` | `4` | Concurrent validations per process |
+
+The first three are surfaced in the validation error message when exceeded; the
+concurrency limit applies as a semaphore and does not appear in responses.
+
 ## Using SHACL validation as a CI/CD gate
 
 Call this function as a pre-publish gate; exit code 1 blocks the pipeline.
diff --git a/semantica/explorer/routes/ontology.py b/semantica/explorer/routes/ontology.py
index e723d166..7fa547af 100644
--- a/semantica/explorer/routes/ontology.py
+++ b/semantica/explorer/routes/ontology.py
@@ -2877,7 +2877,8 @@ async def validate_shacl(
             status="error",
             message=(
                 f"SHACL Turtle size ({len(_shacl_bytes)} bytes) "
-                f"exceeds maximum allowed size ({_MAX_SHACL_TURTLE_BYTES} bytes)."
+                f"exceeds maximum allowed size ({_MAX_SHACL_TURTLE_BYTES} bytes); "
+                f"set SEMANTICA_MAX_SHACL_TURTLE_BYTES to raise the limit."
             ),
             violations=[],
         )
@@ -2894,7 +2895,8 @@ async def validate_shacl(
                 status="error",
                 message=(
                     f"SHACL graph triple count ({len(g)}) "
-                    f"exceeds maximum allowed limit ({_MAX_SHACL_TRIPLES})."
+                    f"exceeds maximum allowed limit ({_MAX_SHACL_TRIPLES}); "
+                    f"set SEMANTICA_MAX_SHACL_TRIPLES to raise the limit."
                 ),
                 violations=[],
             )
@@ -2945,7 +2947,8 @@ async def validate_shacl(
             conforms=False,
             status="error",
             message=(
-                f"SHACL validation timed out after {_MAX_SHACL_TIMEOUT_SECONDS} seconds."
+                f"SHACL validation timed out after {_MAX_SHACL_TIMEOUT_SECONDS} seconds; "
+                f"set SEMANTICA_MAX_SHACL_TIMEOUT to raise the timeout."
             ),
             violations=[],
         )
diff --git a/tests/explorer/test_ontology_subissue3.py b/tests/explorer/test_ontology_subissue3.py
index b24d596a..23192b96 100644
--- a/tests/explorer/test_ontology_subissue3.py
+++ b/tests/explorer/test_ontology_subissue3.py
@@ -735,6 +735,7 @@ onto:PersonShape a sh:NodeShape ;
         payload = response.json()
         assert payload["status"] == "error"
         assert "exceeds maximum allowed size" in payload["message"]
+        assert "SEMANTICA_MAX_SHACL_TURTLE_BYTES" in payload["message"]
 
 
 def test_validate_shacl_rejects_too_many_triples(client):
@@ -757,6 +758,7 @@ onto:PersonShape a sh:NodeShape ;
         payload = response.json()
         assert payload["status"] == "error"
         assert "exceeds maximum allowed limit" in payload["message"]
+        assert "SEMANTICA_MAX_SHACL_TRIPLES" in payload["message"]
 
 
 def test_validate_shacl_handles_timeout(client):
@@ -786,6 +788,7 @@ onto:PersonShape a sh:NodeShape ;
         payload = response.json()
         assert payload["status"] == "error"
         assert "timed out" in payload["message"]
+        assert "SEMANTICA_MAX_SHACL_TIMEOUT" in payload["message"]
 
 
 def test_validate_shacl_returns_unavailable_for_truncated_graph(client):