diff --git a/apps/mcp-server/src/keyword/keyword.service.ts b/apps/mcp-server/src/keyword/keyword.service.ts
index e34b2bbb..1af7c051 100644
--- a/apps/mcp-server/src/keyword/keyword.service.ts
+++ b/apps/mcp-server/src/keyword/keyword.service.ts
@@ -37,6 +37,7 @@ import { isTaskmaestroAvailable } from './taskmaestro-detector';
 import { type ClientType } from '../shared/client-type';
 import { getDiffFiles, analyzeDiffFiles, type DiffAnalysisResult } from './diff-analyzer';
 import { matchStack, type StackMatchInput, type StackMatchResult } from '../agent/stack-matcher';
+import { resolvePlanningContract } from '../mcp/handlers/planning-contract';
 
 /**
  * Options for parseMode method
@@ -992,6 +993,12 @@ export class KeywordService {
         };
       }
 
+      // Attach planning contract regardless of verbosity level
+      const planningContract = resolvePlanningContract(mode, result.delegates_to);
+      if (planningContract) {
+        result.included_agent.planningContract = [...planningContract];
+      }
+
       this.logger.log(`Auto-included agent: ${agentPrompt.displayName} (verbosity: ${verbosity})`);
     }
   }
diff --git a/apps/mcp-server/src/keyword/keyword.types.ts b/apps/mcp-server/src/keyword/keyword.types.ts
index d299338f..a6329906 100644
--- a/apps/mcp-server/src/keyword/keyword.types.ts
+++ b/apps/mcp-server/src/keyword/keyword.types.ts
@@ -388,6 +388,8 @@ export interface IncludedAgent {
   systemPrompt: string;
   /** Agent's areas of expertise */
   expertise: string[];
+  /** Core planning behavior rules that survive all verbosity levels. */
+  planningContract?: string[];
 }
 
 /** Source of Primary Agent selection */
diff --git a/apps/mcp-server/src/mcp/handlers/planning-contract.spec.ts b/apps/mcp-server/src/mcp/handlers/planning-contract.spec.ts
new file mode 100644
index 00000000..46fb26f2
--- /dev/null
+++ b/apps/mcp-server/src/mcp/handlers/planning-contract.spec.ts
@@ -0,0 +1,77 @@
+import { resolvePlanningContract, PLANNING_CONTRACT } from './planning-contract';
+
+describe('planning-contract', () => {
+  describe('PLANNING_CONTRACT', () => {
+    it('should be a readonly array with expected length', () => {
+      expect(PLANNING_CONTRACT).toHaveLength(5);
+    });
+
+    it('should contain question-first guidance rules', () => {
+      expect(PLANNING_CONTRACT[0]).toContain('clarifying question');
+      expect(PLANNING_CONTRACT[1]).toContain('Wait for user confirmation');
+    });
+  });
+
+  describe('resolvePlanningContract', () => {
+    it('should return contract for PLAN mode with technical-planner', () => {
+      const result = resolvePlanningContract('PLAN', 'technical-planner');
+      expect(result).toBe(PLANNING_CONTRACT);
+    });
+
+    it('should return contract for PLAN mode with solution-architect', () => {
+      const result = resolvePlanningContract('PLAN', 'solution-architect');
+      expect(result).toBe(PLANNING_CONTRACT);
+    });
+
+    it('should return contract for PLAN mode with plan-mode', () => {
+      const result = resolvePlanningContract('PLAN', 'plan-mode');
+      expect(result).toBe(PLANNING_CONTRACT);
+    });
+
+    it('should return contract for AUTO mode with auto-mode', () => {
+      const result = resolvePlanningContract('AUTO', 'auto-mode');
+      expect(result).toBe(PLANNING_CONTRACT);
+    });
+
+    it('should return contract for AUTO mode with technical-planner', () => {
+      const result = resolvePlanningContract('AUTO', 'technical-planner');
+      expect(result).toBe(PLANNING_CONTRACT);
+    });
+
+    it('should return undefined for ACT mode', () => {
+      const result = resolvePlanningContract('ACT', 'technical-planner');
+      expect(result).toBeUndefined();
+    });
+
+    it('should return undefined for EVAL mode', () => {
+      const result = resolvePlanningContract('EVAL', 'technical-planner');
+      expect(result).toBeUndefined();
+    });
+
+    it('should return undefined for non-planning agents in PLAN mode', () => {
+      const result = resolvePlanningContract('PLAN', 'code-reviewer');
+      expect(result).toBeUndefined();
+    });
+
+    it('should return undefined for non-planning agents in AUTO mode', () => {
+      const result = resolvePlanningContract('AUTO', 'frontend-developer');
+      expect(result).toBeUndefined();
+    });
+
+    it('should handle case-insensitive mode matching', () => {
+      expect(resolvePlanningContract('plan', 'technical-planner')).toBe(PLANNING_CONTRACT);
+      expect(resolvePlanningContract('Plan', 'technical-planner')).toBe(PLANNING_CONTRACT);
+      expect(resolvePlanningContract('auto', 'auto-mode')).toBe(PLANNING_CONTRACT);
+    });
+
+    it('should return undefined when agentId is undefined', () => {
+      const result = resolvePlanningContract('PLAN');
+      expect(result).toBeUndefined();
+    });
+
+    it('should return undefined when agentId is undefined in AUTO mode', () => {
+      const result = resolvePlanningContract('AUTO');
+      expect(result).toBeUndefined();
+    });
+  });
+});
diff --git a/apps/mcp-server/src/mcp/handlers/planning-contract.ts b/apps/mcp-server/src/mcp/handlers/planning-contract.ts
new file mode 100644
index 00000000..00893276
--- /dev/null
+++ b/apps/mcp-server/src/mcp/handlers/planning-contract.ts
@@ -0,0 +1,39 @@
+/**
+ * Minimum planning behavior contract that must survive standard verbosity.
+ * These rules define the core question-first planning workflow.
+ */
+export const PLANNING_CONTRACT: readonly string[] = [
+  'Ask one clarifying question at a time — do not batch questions.',
+  'Wait for user confirmation before advancing to the next planning stage.',
+  'Use the recommended skill for the current stage (brainstorming for discover, writing-plans for plan).',
+  'Present 2-3 alternative approaches with trade-offs before settling on a direction.',
+  'Break implementation into bite-sized tasks (2-5 minutes each).',
+];
+
+/** Agent IDs that qualify for the planning contract. */
+const PLANNING_AGENT_IDS = new Set([
+  'technical-planner',
+  'solution-architect',
+  'plan-mode',
+  'auto-mode',
+]);
+
+/** Modes that qualify for the planning contract. */
+const PLANNING_MODES = new Set(['PLAN', 'AUTO']);
+
+/**
+ * Determine whether the planning contract should be included.
+ * Returns the contract array if applicable, undefined otherwise.
+ */
+export function resolvePlanningContract(
+  mode: string,
+  agentId?: string,
+): readonly string[] | undefined {
+  if (!PLANNING_MODES.has(mode.toUpperCase())) {
+    return undefined;
+  }
+  if (agentId && PLANNING_AGENT_IDS.has(agentId)) {
+    return PLANNING_CONTRACT;
+  }
+  return undefined;
+}