diff --git a/src/lib/model/schema.test.ts b/src/lib/model/schema.test.ts
index ab9e27a..7eeed74 100644
--- a/src/lib/model/schema.test.ts
+++ b/src/lib/model/schema.test.ts
@@ -104,6 +104,21 @@ describe("dashboard model validation", () => {
     }
   });
 
+  it("rejects duplicate status strip item IDs", () => {
+    const invalid = JSON.parse(JSON.stringify(genericDashboardFixture));
+    invalid.statusStrips[0].items.push({
+      ...invalid.statusStrips[0].items[0],
+    });
+
+    const result = validateDashboardDocument(invalid);
+
+    expect(result.valid).toBe(false);
+    if (!result.valid) {
+      expect(result.errors.join(" ")).toContain("must be unique");
+      expect(result.errors.join(" ")).toContain(invalid.statusStrips[0].items[0].id);
+    }
+  });
+
   it("rejects string values for numeric metric kinds", () => {
     const invalid = JSON.parse(JSON.stringify(genericDashboardFixture));
     invalid.telemetry[0].value.value = "not a percent";
@@ -113,6 +128,24 @@ describe("dashboard model validation", () => {
     expect(result.valid).toBe(false);
   });
 
+  it("rejects percent values outside 0 to 100", () => {
+    const invalid = JSON.parse(JSON.stringify(genericDashboardFixture));
+    invalid.telemetry[0].value.value = 150;
+
+    const result = validateDashboardDocument(invalid);
+
+    expect(result.valid).toBe(false);
+  });
+
+  it("rejects negative values for nonnegative metric kinds", () => {
+    const invalid = JSON.parse(JSON.stringify(genericDashboardFixture));
+    invalid.telemetry[0].value = { kind: "latency", value: -20 };
+
+    const result = validateDashboardDocument(invalid);
+
+    expect(result.valid).toBe(false);
+  });
+
   it("rejects contradictory warning and danger thresholds", () => {
     const invalid = JSON.parse(JSON.stringify(genericDashboardFixture));
     invalid.telemetry[0].thresholds = { warning: 90, danger: 80 };
@@ -125,6 +158,18 @@ describe("dashboard model validation", () => {
     }
   });
 
+  it("rejects percent thresholds above 100", () => {
+    const invalid = JSON.parse(JSON.stringify(genericDashboardFixture));
+    invalid.telemetry[0].thresholds = { warning: 99, danger: 999 };
+
+    const result = validateDashboardDocument(invalid);
+
+    expect(result.valid).toBe(false);
+    if (!result.valid) {
+      expect(result.errors.join(" ")).toContain("percent thresholds");
+    }
+  });
+
   it("rejects thresholds on text metric values", () => {
     const invalid = JSON.parse(JSON.stringify(genericDashboardFixture));
     invalid.telemetry[0].value = { kind: "text", value: "available" };
diff --git a/src/lib/model/schema.ts b/src/lib/model/schema.ts
index d338468..e0215a4 100644
--- a/src/lib/model/schema.ts
+++ b/src/lib/model/schema.ts
@@ -64,16 +64,25 @@ const DatasourceReferenceSchema = Type.Union([
   ExternalDatasourceSchema,
 ]);
 
-const NumericMetricValueSchema = Type.Object(
+const PercentMetricValueSchema = Type.Object(
+  {
+    kind: Type.Literal("percent"),
+    value: Type.Number({ minimum: 0, maximum: 100 }),
+    unit: Type.Optional(Type.String({ minLength: 1 })),
+    precision: Type.Optional(Type.Integer({ minimum: 0, maximum: 4 })),
+  },
+  { additionalProperties: false },
+);
+
+const NonNegativeMetricValueSchema = Type.Object(
   {
     kind: Type.Union([
-      Type.Literal("percent"),
       Type.Literal("bytes"),
       Type.Literal("temperature"),
       Type.Literal("latency"),
       Type.Literal("number"),
     ]),
-    value: Type.Number(),
+    value: Type.Number({ minimum: 0 }),
     unit: Type.Optional(Type.String({ minLength: 1 })),
     precision: Type.Optional(Type.Integer({ minimum: 0, maximum: 4 })),
   },
@@ -90,14 +99,15 @@ const TextMetricValueSchema = Type.Object(
 );
 
 const MetricValueSchema = Type.Union([
-  NumericMetricValueSchema,
+  PercentMetricValueSchema,
+  NonNegativeMetricValueSchema,
   TextMetricValueSchema,
 ]);
 
 const ThresholdSchema = Type.Object(
   {
-    warning: Type.Optional(Type.Number()),
-    danger: Type.Optional(Type.Number()),
+    warning: Type.Optional(Type.Number({ minimum: 0 })),
+    danger: Type.Optional(Type.Number({ minimum: 0 })),
   },
   { additionalProperties: false, minProperties: 1 },
 );
diff --git a/src/lib/model/validation.ts b/src/lib/model/validation.ts
index 7a79b54..f70b0cd 100644
--- a/src/lib/model/validation.ts
+++ b/src/lib/model/validation.ts
@@ -135,6 +135,14 @@ function validateSemanticRules(document: DashboardDocument): SemanticValidationI
     );
   });
 
+  document.statusStrips.forEach((strip, stripIndex) => {
+    collectDuplicateIdIssues(
+      `statusStrips/${stripIndex}/items`,
+      strip.items,
+      issues,
+    );
+  });
+
   collectMissingReferenceIssues(
     "layout/telemetry",
     document.layout.telemetry,
@@ -171,6 +179,20 @@ function validateSemanticRules(document: DashboardDocument): SemanticValidationI
       );
     }
 
+    if (
+      card.value.kind === "percent" &&
+      ((card.thresholds?.warning !== undefined && card.thresholds.warning > 100) ||
+        (card.thresholds?.danger !== undefined && card.thresholds.danger > 100))
+    ) {
+      issues.push(
+        semanticIssue(
+          `/telemetry/${index}/thresholds`,
+          "percent thresholds must be between 0 and 100",
+          { id: card.id },
+        ),
+      );
+    }
+
     const warning = card.thresholds?.warning;
     const danger = card.thresholds?.danger;
     if (warning !== undefined && danger !== undefined && warning > danger) {