# run-algo-locate-root-cause

`station__microgram__run-algo-locate-root-cause` · external (needs EXECUTION_BACKEND_URL configured) · domain `microgram` · pv-relevance `pv-core`

Algorithm 10 (LOCATE): Boundary contraction search. Takes a failure and systematically narrows the search space through successive comparisons (κ) at each location (λ), halving the boundary (∂) until root cause is located.

> **Note:** This tool routes through an external execution backend. If `EXECUTION_BACKEND_URL` is unset on the server, calls return JSON-RPC error `-32603 "Tool execution backend not configured"`. Tools with `backend: native` execute in-process and are always callable.

## Agent metadata

- `idempotent`: unknown
- `read_only`: unknown
- `expected_latency_ms`: unknown (not yet contract-tested)
- `cost_tokens_estimate`: unknown

## Input schema

- `error_reproducible` *boolean* (required) — Input parameter: error_reproducible
- `recent_change` *boolean* (required) — Input parameter: recent_change
- `error_in_tests` *boolean* (required) — Input parameter: error_in_tests
- `failure_layer` *string* (required) — Input parameter: failure_layer

## Example call

```json
POST /api/mcp
Content-Type: application/json

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "station__microgram__run-algo-locate-root-cause",
    "arguments": {
      "error_reproducible": false,
      "recent_change": false,
      "error_in_tests": false,
      "failure_layer": ""
    }
  }
}
```

## Related

- [/tools](/tools) — all 3062 tools
- [/tools/microgram__run-algo-locate-root-cause](/tools/microgram__run-algo-locate-root-cause) — HTML page
- [/tools/microgram__run-algo-locate-root-cause/json](/tools/microgram__run-algo-locate-root-cause/json) — JSON form (agent-friendly)
- [/api/mcp](/api/mcp) — endpoint
- [/AGENTS.md](/AGENTS.md) — agent guide