diff --git a/packages/core/src/tools/definitions/model-family-sets/gemini-3.ts b/packages/core/src/tools/definitions/model-family-sets/gemini-3.ts
index a532cac8ba..3ee437c5c3 100644
--- a/packages/core/src/tools/definitions/model-family-sets/gemini-3.ts
+++ b/packages/core/src/tools/definitions/model-family-sets/gemini-3.ts
@@ -132,7 +132,7 @@ export const GEMINI_3_SET: CoreToolSet = {
   grep_search_ripgrep: {
     name: GREP_TOOL_NAME,
     description:
-      'Searches for a regular expression pattern within file contents.',
+      'Searches for a regular expression pattern within file contents. This tool is FAST and optimized, powered by ripgrep. PREFERRED over standard `run_shell_command("grep ...")` due to better performance and automatic output limiting (max 20k matches).',
     parametersJsonSchema: {
       type: 'object',
       properties: {