fix: Ollama with gemma4 can't see tool functions

[futurelink]

Ollama with gemma4 can't see tool functions passed to a chat request.

[2026-07-20T10:34:53Z INFO  ollama_agent] Using model 'gemma4:26b'

Request: Object {"messages": Array [Object {"content": String("You are careful assistant. \n* If you have not tool or function to make an operation do not guess.\n* If you have no access to a data requested - do not guess, say 'I have no access to that data'."), "role": String("system")}, Object {"content": String("Hello! What is in a tools section of this message?"), "role": String("user")}], "model": String("gemma4:26b"), "options": Object {"temperature": Number(0.0)}, "stream": Bool(false), "tools": Array [Object {"description": String("Run some Python code"), "name": String("run_python_code"), "parameters": Object {"code": String("string")}}, Object {"description": String("Get a list of files in a specific directory"), "name": String("list_files"), "parameters": Object {"properties": Object {"path": Object {"description": String("A path to list"), "type": String("string")}}, "required": Array [String("path")], "type": String("object")}}]}

Response: ChatResponse { message: ChatMessage { role: Assistant, content: "In the tools section of this message, there are two empty function declarations (`declaration`) that do not contain any specific names or descriptions.", images: None, tool_calls: None }, done: true, done_reason: Some("stop"), model: Some("gemma4:26b"), created_at: Some("2026-07-20T10:35:04.535421198Z"), total_duration: Some(10754068384), load_duration: Some(8323087277), prompt_eval_count: Some(95), prompt_eval_duration: Some(141105000), eval_count: Some(294), eval_duration: Some(2287956000) }

Solution: wrap ToolDefinition into standard 'function' object. After making the change a response was:

esponse: ChatResponse { message: ChatMessage { role: Assistant, content: "The \"tools section\" of this message contains definitions for two specific functions that I can use to perform tasks:\n\n1.  **`run_python_code`**: This tool allows me to execute Python code to perform calculations, process data, or solve complex problems.\n2.  **`list_files`**: This tool allows me to view the contents of a specific directory by providing a file path.", images: None, tool_calls: None }, done: true, done_reason: Some("stop"), model: Some("gemma4:26b"), created_at: Some("2026-07-20T10:37:58.23567988Z"), total_duration: Some(2470828054), load_duration: Some(253039555), prompt_eval_count: Some(151), prompt_eval_duration: Some(77845000), eval_count: Some(286), eval_duration: Some(2062304000) }