OFAT Matrix LLM Tuning: A Methodology for Picking Sampling Params, Tool Configs, and Prompts Without Guessing

OFAT Matrix LLM Tuning#

When a new provider or model lands and you have to decide what temperature, max_tokens, tool_choice, prompt-shape, and turn budget to ship in production, the default is to pick by hunch. Read the model card, copy a partner adapter’s defaults, ship. A week later you find out reasoning_effort=high doubled cost for no quality gain, max_tokens=2048 silently truncated half your tier-3 runs, and the “prompt-rich” pattern you copied from grok-4.3 actively hurts kimi.

An End-to-End Workflow for Evaluating & Tuning Local LLMs for Agents

Decision-first: Follow this order and you’ll have a deployable model + tuned config in days, not weeks: (1) scope the hardware, (2) shortlist by active params, (3) per-model OFAT matrix, (4) run serially with an OOM guard (smoke first), (5) write a finding card per model, (6) decide. The expensive mistakes are skipping the smoke step, sweeping more than one factor at once, and trusting a single run.

Scope & freshness: Process is model/hardware-independent; the worked numbers are from a 2026-05 effort on a GB10 (128 GB) + an Apple-Silicon Mac, evaluating local MoE models vs cloud baselines for agentic coding. Re-validate the findings, not the workflow.

Benchmarking Local LLMs for Agentic Coding

Decision-first: Evaluate on the agent loop (read/edit/test/push), not one-shot patches. Use a multi-file execution-stamina task as your discriminator, tune OFAT at N≥3, and distinguish turn-ceiling vs token-ceiling vs capability-ceiling — only the last is unfixable by config.

Scope & freshness: Methodology is durable; the named results are 2026-05 snapshots — re-run the harness for current models.

Why public leaderboard scores mislead#

SWE-bench-style and chat leaderboards measure something adjacent to, but not the same as, autonomous tool-using coding. A model can score well on one-shot patch generation and still fail as an agent because the agent loop demands sustained, multi-turn behavior: read files, edit several, run tests, react to failures, and push — without giving up, looping, or declaring “done” early. Evaluate on the loop you’ll actually run.

Agent Evaluation and Testing: Measuring What Matters in Agent Performance

Agent Evaluation and Testing#

You cannot improve what you cannot measure. Agent evaluation is harder than traditional software testing because agents are non-deterministic, their behavior depends on prompt wording, and the same input can produce multiple valid outputs. But “it is hard” is not an excuse for not doing it. This article provides a step-by-step framework for building an agent evaluation pipeline that catches regressions, compares configurations, and quantifies real-world performance.