diff --git a/__tests__/explore-output-budget.test.ts b/__tests__/explore-output-budget.test.ts
index efe302fb7..7843bebd2 100644
--- a/__tests__/explore-output-budget.test.ts
+++ b/__tests__/explore-output-budget.test.ts
@@ -197,7 +197,10 @@ describe('codegraph_explore output respects the adaptive budget', () => {
     const result = await handler.execute('codegraph_explore', { query: 'Session method helper' });
     const text = result.content?.[0]?.text ?? '';
     expect(text).not.toContain('### Additional relevant files');
-    expect(text).not.toContain('Complete source code is included above');
+    // The completeness note, which reads "Complete source for 1 file is
+    // included above…" on this fixture ("Verbatim source for N files…" after
+    // a trim).
+    expect(text).not.toContain('is included above');
     expect(text).not.toContain('advisory only, NOT a quota');
   });
 
@@ -213,6 +216,9 @@ describe('codegraph_explore output respects the adaptive budget', () => {
       const text = result.content?.[0]?.text ?? '';
       expect(text).toContain('advisory only, NOT a quota');
       expect(text).toContain('extra calls are never rejected or rate-limited');
+      // The completeness note is on here, so the small tier's check for its
+      // absence above still names text the note has.
+      expect(text).toContain('is included above');
       expect(text).not.toContain('remaining calls');
       expect(text).not.toContain('Synthesize once');
     } finally {
diff --git a/src/mcp/tools.ts b/src/mcp/tools.ts
index e15c8386d..5adf1cfb2 100644
--- a/src/mcp/tools.ts
+++ b/src/mcp/tools.ts
@@ -296,7 +296,7 @@ export interface ExploreOutputBudget {
   includeRelationships: boolean;
   /** Include the "Additional relevant files (not shown)" trailing list. */
   includeAdditionalFiles: boolean;
-  /** Include the "Complete source code is included above…" reminder. */
+  /** Include the "… source for N files is included above" reminder. */
   includeCompletenessSignal: boolean;
   /**
    * Include the advisory exploration-guidance note at the end. Purely
@@ -1832,12 +1832,11 @@ export const tools: ToolDefinition[] = [
       properties: {
         query: {
           type: 'string',
-          description: 'Symbol names, file names, or short code terms to explore (e.g., "AuthService loginUser session-manager", "GraphTraverser BFS impact traversal.ts"). For a flow question, name the symbols spanning the flow (e.g. "mutateElement renderScene"). A natural-language question works too — no prior codegraph_search needed.',
+          description: 'Symbol names, file names, or short code terms to explore (e.g., "AuthService loginUser session-manager", "GraphTraverser BFS impact traversal.ts"). For a flow question, name the symbols spanning the flow (e.g. "mutateElement renderScene"). A natural-language question works too.',
         },
         maxFiles: {
           type: 'number',
-          description: 'Maximum number of files to include source code from (default: 12)',
-          default: 12,
+          description: 'Maximum number of files to return source from, 1–20. Omit it to use a default sized to the project (4 files below 150 indexed files, 5 below 500, 8 otherwise). Total output is also capped by characters (about 13K–24K by project size), so a higher maxFiles spreads that budget over more files rather than returning more text.',
         },
         projectPath: projectPathProperty,
       },