GitHub Copilot SDK tools are called with empty params {} when querying Prometheus / Loki

[Haddajii]

I’m building an SRE-style assistant using GitHub Copilot SDK (Python) with tool calling.

Context

• Infrastructure: OpenStack (controller, compute, storage nodes)
• Monitoring node runs:
  • Prometheus (metrics from other nodes)
  • Loki + Promtail (logs from other nodes)
  • Grafana (everything works fine)
• I’m running my Copilot SDK + FastAPI app on the monitoring node

What I’m trying to do

I defined tools using @define_tool so the AI can:

• Query Prometheus for metrics
• Query Loki for logs
• Act like an SRE (e.g. “check CPU usage”, “show error logs for nova”)

code

from copilot.tools import define_tool
import requests

LOKI_URL = "http://localhost:3100/loki/api/v1/query"

@define_tool(
    description="Query Loki logs using LogQL. Use this to fetch logs from OpenStack nodes."
)
async def query_loki(query: str, limit: int = 50) -> dict:
    print("[TOOL] Loki called with:", query, limit)

    try:
        response = requests.get(
            LOKI_URL,
            params={"query": query, "limit": limit},
            timeout=5
        )
        data = response.json()

        logs = []
        for stream in data.get("data", {}).get("result", []):
            for value in stream.get("values", []):
                logs.append(value[1])

        return {
            "query": query,
            "log_count": len(logs),
            "logs": logs[:limit]
        }

    except Exception as e:
        return {"error": str(e)}

Problem

When I ask the AI something like:

"Show me recent error logs from compute nodes"
The tool does get called, but:

loki called with param: {}

so:

• The model decides to call the tool
• But it passes empty parameters
• Result: no logs, no metrics

What I’ve verified

• Prometheus endpoints work via browser & curl
• localhost is correct (everything runs on the monitoring node)
• Streaming responses are enabled

Questions

• How do I force or strongly guide Copilot SDK to send required parameters to tools?
• Is there a recommended way to define tool schemas so params are never empty?
• Is this expected behavior with Copilot SDK tool calling?
• Any best practices for building observability / SRE agents with Copilot SDK?