count_tokens
Calculate token counts for text using Gemini models to manage API usage and optimize input length.
Instructions
Count tokens for a given text with a specific model
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| text | Yes | Text to count tokens for | |
| model | No | Model to use for token counting | gemini-2.5-flash |
Implementation Reference
- src/enhanced-stdio-server.ts:698-736 (handler)The handler function that executes the count_tokens tool. It takes text and optional model, calls the Gemini API's countTokens method, and returns the token count in MCP response format.
private async countTokens(id: any, args: any): Promise<MCPResponse> { try { const model = args.model || 'gemini-2.5-flash'; const result = await this.genAI.models.countTokens({ model, contents: [{ parts: [{ text: args.text }], role: 'user' }] }); return { jsonrpc: '2.0', id, result: { content: [{ type: 'text', text: `Token count: ${result.totalTokens}` }], metadata: { tokenCount: result.totalTokens, model } } }; } catch (error) { return { jsonrpc: '2.0', id, error: { code: -32603, message: error instanceof Error ? error.message : 'Internal error' } }; } } - src/enhanced-stdio-server.ts:308-323 (schema)Input schema definition for the count_tokens tool, specifying required 'text' parameter and optional 'model'.
inputSchema: { type: 'object', properties: { text: { type: 'string', description: 'Text to count tokens for' }, model: { type: 'string', description: 'Model to use for token counting', enum: Object.keys(GEMINI_MODELS), default: 'gemini-2.5-flash' } }, required: ['text'] } - src/enhanced-stdio-server.ts:305-324 (registration)Tool registration in the available tools list, including name, description, and input schema.
{ name: 'count_tokens', description: 'Count tokens for a given text with a specific model', inputSchema: { type: 'object', properties: { text: { type: 'string', description: 'Text to count tokens for' }, model: { type: 'string', description: 'Model to use for token counting', enum: Object.keys(GEMINI_MODELS), default: 'gemini-2.5-flash' } }, required: ['text'] } }, - src/enhanced-stdio-server.ts:480-481 (registration)Dispatch case in handleToolCall method that routes count_tokens calls to the handler function.
case 'count_tokens': return await this.countTokens(request.id, args);