Request params reference

Field	Type	Default
`task`	`mcp.types.TaskMetadata \| None`	`None`
`meta`	`mcp.types.RequestParams.Meta \| None`	`None`
`messages`	`list[mcp.types.SamplingMessage]`	`[]`
`modelPreferences`	`mcp.types.ModelPreferences \| None`	`None`
`systemPrompt`	`str \| None`	`None`
`includeContext`	`Literal['none', 'thisServer', 'allServers'] \| None`	`None`
`temperature`	`float \| None`	`None`
`maxTokens`	`int \| None`	`None`
`stopSequences`	`list[str] \| None`	`None`
`metadata`	`dict[str, Any] \| None`	`None`
`tools`	`list[mcp.types.Tool] \| None`	`None`
`toolChoice`	`mcp.types.ToolChoice \| None`	`None`
`model`	`str \| None`	`None`
`use_history`	`bool`	`True`
`max_iterations`	`int`	`199`
`parallel_tool_calls`	`bool`	`True`
`response_format`	`Any \| None`	`None`
`structured_schema`	`dict[str, Any] \| None`	`None`
`structured_tool_policy`	`Literal['auto', 'always', 'defer', 'no_tools']`	`'auto'`
`template_vars`	`dict[str, Any]`	`{}`
`mcp_metadata`	`dict[str, Any] \| None`	`None`
`tool_execution_handler`	`Any \| None`	`None`
`emit_loop_progress`	`bool`	`False`
`tool_result_mode`	`Literal['postprocess', 'passthrough', 'selectable']`	`'postprocess'`
`batch_context`	`fast_agent.llm.request_params.BatchRequestContext \| None`	`None`
`streaming_timeout`	`float \| None`	`120.0`
`top_p`	`float \| None`	`None`
`top_k`	`int \| None`	`None`
`min_p`	`float \| None`	`None`
`presence_penalty`	`float \| None`	`None`
`frequency_penalty`	`float \| None`	`None`
`repetition_penalty`	`float \| None`	`None`
`service_tier`	`Literal['fast', 'flex'] \| None`	`None`