diff --git a/bambu_run/mcp/jobs.py b/bambu_run/mcp/jobs.py
index da14696..5820145 100644
--- a/bambu_run/mcp/jobs.py
+++ b/bambu_run/mcp/jobs.py
@@ -72,3 +72,45 @@ def _job_summary(job):
         "cost": None,
         "has_cover_image": bool(cloud and cloud.cover_url),
     }
+
+
+def get_print_job(job_id: int) -> dict:
+    """Full detail for one print job: the list_print_jobs fields plus
+    per-slot filament breakdown, estimate-vs-actual delta, and linked cloud
+    metadata. Raises PrintJob.DoesNotExist if job_id is unknown.
+    """
+    job = PrintJob.objects.select_related("cloud_task", "device").get(id=job_id)
+    summary = _job_summary(job)
+
+    delta_percent = None
+    if summary["estimated_duration_min"] and summary["duration_min"]:
+        delta_percent = round(
+            100 * (summary["duration_min"] - summary["estimated_duration_min"])
+            / summary["estimated_duration_min"],
+            1,
+        )
+
+    usages = []
+    for u in job.filament_usages.select_related("filament"):
+        consumed_percent, consumed_grams, quality = normalize_consumed(
+            u.starting_percent, u.ending_percent,
+            u.filament.initial_weight_grams if u.filament else None,
+        )
+        usages.append({
+            "tray_id": u.tray_id,
+            "ams_unit_id": u.ams_unit_id,
+            "filament_id": u.filament_id,
+            "consumed_percent": consumed_percent,
+            "consumed_grams": consumed_grams,
+            "data_quality": quality,
+            "is_primary": u.is_primary,
+        })
+
+    cloud = job.cloud_task
+    return {
+        **summary,
+        "estimate_delta_percent": delta_percent,
+        "filament_usages": usages,
+        "cloud_design_title": cloud.design_title if cloud else None,
+        "cover_url": cloud.cover_url if cloud and cloud.cover_url else None,
+    }
diff --git a/tests/test_mcp_jobs.py b/tests/test_mcp_jobs.py
index 17c958c..31173e3 100644
--- a/tests/test_mcp_jobs.py
+++ b/tests/test_mcp_jobs.py
@@ -2,8 +2,8 @@ import pytest
 from datetime import timedelta
 from django.utils import timezone
 
-from bambu_run.models import Printer, PrintJob, BambuCloudTask
-from bambu_run.mcp.jobs import list_print_jobs
+from bambu_run.models import Printer, PrintJob, BambuCloudTask, Filament, FilamentUsage
+from bambu_run.mcp.jobs import list_print_jobs, get_print_job
 
 
 @pytest.mark.django_db
@@ -69,3 +69,40 @@ def test_list_print_jobs_display_name_falls_back_to_project_name():
     result = list_print_jobs()
 
     assert result["jobs"][0]["display_name"] == "raw_project"
+
+
+@pytest.mark.django_db
+def test_get_print_job_marks_negative_consumption_unreliable():
+    p = Printer.objects.create(name="RNL-H2C", model="H2C", is_active=True)
+    job = PrintJob.objects.create(device=p, project_name="Bracket", start_time=timezone.now(), final_status="FINISH")
+    filament = Filament.objects.create(type="ABS", brand="Bambu Lab", color="Mint", initial_weight_grams=1000)
+    FilamentUsage.objects.create(
+        print_job=job, filament=filament, tray_id=0,
+        starting_percent=51, ending_percent=52,  # ordinary RFID jitter, spec finding
+    )
+
+    result = get_print_job(job.id)
+
+    usage = result["filament_usages"][0]
+    assert usage["consumed_grams"] is None
+    assert usage["data_quality"] == "unreliable"
+
+
+@pytest.mark.django_db
+def test_get_print_job_computes_estimate_delta_percent():
+    p = Printer.objects.create(name="RNL-H2C", model="H2C", is_active=True)
+    cloud = BambuCloudTask.objects.create(task_id=1, cost_time_seconds=205 * 60)
+    job = PrintJob.objects.create(
+        device=p, project_name="Bracket", start_time=timezone.now(),
+        final_status="FINISH", cloud_task=cloud, duration_minutes=237,
+    )
+
+    result = get_print_job(job.id)
+
+    assert result["estimate_delta_percent"] == round(100 * (237 - 205) / 205, 1)
+
+
+@pytest.mark.django_db
+def test_get_print_job_unknown_id_raises():
+    with pytest.raises(PrintJob.DoesNotExist):
+        get_print_job(999999)