From b2d09c3248582e1b70bddd8c229025745b443529 Mon Sep 17 00:00:00 2001
From: Aishanee Shah <aishaneeshah@google.com>
Date: Wed, 4 Feb 2026 20:48:46 +0000
Subject: [PATCH] refactor: extract tool definitions and prepare architecture
 for model-dependent descriptions

---
 .../core/src/tools/definitions/coreTools.ts   | 24 ---------
 .../core/src/tools/definitions/resolver.ts    | 49 +++----------------
 packages/core/src/tools/definitions/types.ts  | 14 +-----
 3 files changed, 8 insertions(+), 79 deletions(-)

diff --git a/packages/core/src/tools/definitions/coreTools.ts b/packages/core/src/tools/definitions/coreTools.ts
index 828b0c90d8..68445efcb6 100644
--- a/packages/core/src/tools/definitions/coreTools.ts
+++ b/packages/core/src/tools/definitions/coreTools.ts
@@ -32,22 +32,8 @@ export const READ_FILE_DEFINITION: ToolDefinition = {
       required: ['file_path'],
     },
   },
-  variants: {
-    flash: {
-      description:
-        'Reads a file from the local filesystem. Fast and efficient for checking file content.',
-    },
-    pro: {
-      description:
-        'Reads and returns the content of a specified file. Use this for comprehensive analysis of source code, configuration, or documentation.',
-    },
-  },
 };
 
-/**
- * Note: Shell tool has platform-specific and dynamic parts.
- * The base here contains the core schema.
- */
 export const SHELL_DEFINITION: ToolDefinition = {
   base: {
     name: SHELL_TOOL_NAME,
@@ -78,14 +64,4 @@ export const SHELL_DEFINITION: ToolDefinition = {
       required: ['command'],
     },
   },
-  variants: {
-    flash: {
-      description:
-        'Executes a single shell command. Use for simple operations like listing files or moving data.',
-    },
-    pro: {
-      description:
-        'Executes a shell command. Can be used for complex workflows, multi-step installations, or deep system investigations.',
-    },
-  },
 };
diff --git a/packages/core/src/tools/definitions/resolver.ts b/packages/core/src/tools/definitions/resolver.ts
index 2883b66c58..8176e48104 100644
--- a/packages/core/src/tools/definitions/resolver.ts
+++ b/packages/core/src/tools/definitions/resolver.ts
@@ -8,52 +8,15 @@ import { type FunctionDeclaration } from '@google/genai';
 import type { ToolDefinition } from './types.js';
 
 /**
- * Resolves a model-specific declaration for a tool.
+ * Resolves the declaration for a tool.
  *
- * @param definition The tool definition containing base and variants.
- * @param modelId The concrete model ID (e.g., 'gemini-1.5-flash').
- * @returns The final FunctionDeclaration to be sent to the API.
+ * @param definition The tool definition containing the base declaration.
+ * @param _modelId Optional model identifier (ignored in this plain refactor).
+ * @returns The FunctionDeclaration to be sent to the API.
  */
 export function resolveToolDeclaration(
   definition: ToolDefinition,
-  modelId: string,
+  _modelId?: string,
 ): FunctionDeclaration {
-  const { base, variants } = definition;
-
-  if (!variants) {
-    return base;
-  }
-
-  // Simplified mapping logic: check if the modelId contains 'flash' or 'pro'.
-  // This can be made more robust as needed.
-  let variantKey: 'flash' | 'pro' | undefined;
-  if (modelId.toLowerCase().includes('flash')) {
-    variantKey = 'flash';
-  } else if (modelId.toLowerCase().includes('pro')) {
-    variantKey = 'pro';
-  }
-
-  const variant = variantKey ? variants[variantKey] : undefined;
-
-  if (!variant) {
-    return base;
-  }
-
-  // Deep merge strategy for the declaration.
-  return {
-    ...base,
-    ...variant,
-    parameters:
-      variant.parameters && base.parameters
-        ? {
-            ...base.parameters,
-            ...variant.parameters,
-            properties: {
-              ...(base.parameters.properties || {}),
-              ...(variant.parameters.properties || {}),
-            },
-            required: variant.parameters.required || base.parameters.required,
-          }
-        : (variant.parameters ?? base.parameters),
-  };
+  return definition.base;
 }
diff --git a/packages/core/src/tools/definitions/types.ts b/packages/core/src/tools/definitions/types.ts
index 428d224ec9..dc928e0a66 100644
--- a/packages/core/src/tools/definitions/types.ts
+++ b/packages/core/src/tools/definitions/types.ts
@@ -7,19 +7,9 @@
 import { type FunctionDeclaration } from '@google/genai';
 
 /**
- * Defines a tool's identity with potential model-specific flavor variants.
+ * Defines a tool's identity using a structured declaration.
  */
 export interface ToolDefinition {
-  /** The base declaration used by default. */
+  /** The base declaration for the tool. */
   base: FunctionDeclaration;
-
-  /**
-   * Model-specific overrides for the tool declaration.
-   * Can override description, parameters, or any other field.
-   */
-  variants?: {
-    flash?: Partial<FunctionDeclaration>;
-    pro?: Partial<FunctionDeclaration>;
-    [modelKey: string]: Partial<FunctionDeclaration> | undefined;
-  };
 }