> ## Documentation Index
> Fetch the complete documentation index at: https://qitor.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Function tool migration

> QitOS G5 · Function tool migration

Historical ToolMeta/decorator examples are not the G5 authoring contract. Use function\_tool from qitos.core.function\_tool\_decorator for pure functions; class tools implement BaseTool.execute(args, runtime\_context) with ToolSpec. Register them with ToolRegistry. Keep permissions and effect declarations explicit; run is a compatibility path.

[Learning path](/tutorials/index) · [Configuration](/reference/configuration) · [Contributing](/contributing/development).