diff --git a/QUICKSTART.adoc b/QUICKSTART.adoc
index e6514ec..78f63ad 100644
--- a/QUICKSTART.adoc
+++ b/QUICKSTART.adoc
@@ -36,6 +36,22 @@ worse on none), *pareto-regression* (worse on at least one, better on none),
 description), or *neutral*. Advisory by default; `--check --pr-body pr.txt`
 fails the run on an undocumented, measured regression or trade-off.
 
+[IMPORTANT]
+====
+*`--check` cannot block a merge today, by design.* Only objectives backed by
+`Measured` or `Calibrated` inputs may fail a run, and every resource figure
+OikosBot currently produces is a heuristic `Estimated` value — the calibration
+framework at `crates/oikosbot-analysis/src/calibration.rs` exists but is not
+yet wired into the analyzer, which still uses a naive complexity-derived
+estimate.
+
+So `--check` reports and warns, but always exits 0. It says so *loudly* — a
+`::warning::` annotation naming the confidence level — rather than passing
+silently. A gate that quietly does nothing is indistinguishable from one that
+passed, which is precisely the failure mode OikosBot exists to find.
+Enforcement becomes real when calibration is wired in.
+====
+
 === Per-repo configuration
 
 `check`, `report`, and `compare` honor an `.oikos.yml` in the analyzed
diff --git a/action.yml b/action.yml
index e31fa3e..529349a 100644
--- a/action.yml
+++ b/action.yml
@@ -49,7 +49,12 @@ inputs:
     required: false
     default: ''
   check:
-    description: 'compare mode: fail on an undocumented, measured Pareto regression/trade-off (true/false)'
+    description: >-
+      compare mode: fail on an undocumented, measured Pareto
+      regression/trade-off. NOTE: cannot block today — every resource figure is
+      a heuristic Estimated value and only Measured/Calibrated inputs may
+      fail a run, so this warns loudly and exits 0 until calibration is wired
+      in (see QUICKSTART).
     required: false
     default: 'false'
   image:
diff --git a/crates/oikosbot-cli/src/main.rs b/crates/oikosbot-cli/src/main.rs
index f9d6a73..0b26b5b 100644
--- a/crates/oikosbot-cli/src/main.rs
+++ b/crates/oikosbot-cli/src/main.rs
@@ -364,8 +364,27 @@ fn main() -> Result<()> {
                 oikosbot_pareto::ParetoVerdict::Regression
                     | oikosbot_pareto::ParetoVerdict::TradeOff
             );
-            if check && needs_documentation && assessment.actionable && documented != Some(true) {
-                std::process::exit(1);
+            if check && needs_documentation && documented != Some(true) {
+                if assessment.actionable {
+                    std::process::exit(1);
+                }
+                // Enforcement was asked for and cannot be delivered: the
+                // driving objectives rest on heuristic estimates, which by
+                // design may not block a merge. Say so unmissably. A gate
+                // that silently no-ops is indistinguishable from one that
+                // passed, which is the failure mode this tool exists to
+                // find — so it must never be silent about its own limits.
+                eprintln!(
+                    "::warning::--check requested but NOT enforced: the objectives driving \
+                     this {} verdict are {:?}, and only Measured or Calibrated inputs may \
+                     block. Reported as advisory. See docs: enforcement is inert while \
+                     resource figures remain heuristic estimates.",
+                    match assessment.verdict {
+                        oikosbot_pareto::ParetoVerdict::Regression => "pareto-regression",
+                        _ => "trade-off",
+                    },
+                    confidence,
+                );
             }
         }