allow use of AGENTS.md as well as PROMPT.md (#3317)

Co-authored-by: célina <[email protected]>

Author: evalstate

src/huggingface_hub/inference/_mcp/cli.py

@@ -33,7 +33,7 @@ async def run_agent(
 
     Args:
         agent_path (`str`, *optional*):
-            Path to a local folder containing an `agent.json` and optionally a custom `PROMPT.md` file or a built-in agent stored in a Hugging Face dataset.
+            Path to a local folder containing an `agent.json` and optionally a custom `PROMPT.md` or `AGENTS.md` file or a built-in agent stored in a Hugging Face dataset.
 
     """
     _patch_anyio_open_process()  # Hacky way to prevent stdio connections to be stopped by Ctrl+C

src/huggingface_hub/inference/_mcp/constants.py

@@ -8,7 +8,7 @@
 
 
 FILENAME_CONFIG = "agent.json"
-FILENAME_PROMPT = "PROMPT.md"
+PROMPT_FILENAMES = ("PROMPT.md", "AGENTS.md")
 
 DEFAULT_AGENT = {
     "model": "Qwen/Qwen2.5-72B-Instruct",

src/huggingface_hub/inference/_mcp/utils.py

@@ -11,7 +11,7 @@
 from huggingface_hub import snapshot_download
 from huggingface_hub.errors import EntryNotFoundError
 
-from .constants import DEFAULT_AGENT, DEFAULT_REPO_ID, FILENAME_CONFIG, FILENAME_PROMPT
+from .constants import DEFAULT_AGENT, DEFAULT_REPO_ID, FILENAME_CONFIG, PROMPT_FILENAMES
 from .types import AgentConfig
 
 
@@ -93,8 +93,12 @@ def _read_dir(directory: Path) -> Tuple[AgentConfig, Optional[str]]:
             raise FileNotFoundError(f" Config file not found in {directory}! Please make sure it exists locally")
 
         config: AgentConfig = json.loads(cfg_file.read_text(encoding="utf-8"))
-        prompt_file = directory / FILENAME_PROMPT
-        prompt: Optional[str] = prompt_file.read_text(encoding="utf-8") if prompt_file.exists() else None
+        prompt: Optional[str] = None
+        for filename in PROMPT_FILENAMES:
+            prompt_file = directory / filename
+            if prompt_file.exists():
+                prompt = prompt_file.read_text(encoding="utf-8")
+                break
         return config, prompt
 
     if agent_path is None: