server : add documentation for `parallel_tool_calls` param (#15647)

Co-authored-by: Pierre F <no@p.e>

docs/function-calling.md

@@ -21,6 +21,8 @@ Function calling is supported for all models (see https://github.com/ggml-org/ll
   - Use `--chat-template-file` to override the template when appropriate (see examples below)
   - Generic support may consume more tokens and be less efficient than a model's native format.
 
+- Multiple/parallel tool calling is supported on some models but disabled by default, enable it by passing `"parallel_tool_calls": true` in the completion endpoint payload.
+
 <details>
 <summary>Show some common templates and which format handler they use</summary>
 

tools/server/README.md

@@ -1143,6 +1143,8 @@ The `response_format` parameter supports both plain JSON output (e.g. `{"type":
 
 `parse_tool_calls`: Whether to parse the generated tool call.
 
+`parallel_tool_calls` : Whether to enable parallel/multiple tool calls (only supported on some models, verification is based on jinja template).
+
 *Examples:*
 
 You can use either Python `openai` library with appropriate checkpoints: