We used to believe that a better model automatically meant better results. And that’s true to some degree, but the reality is that most people aren’t using all the available tools and techniques to get the most out of the model.
For example, context management is key. Providing good AGENTS.md and CLAUDE.md files gives agents a solid baseline from the start.
The harness is also important because the model is only one part of the system. The harness controls the context the model receives, the tools it can use, its permissions, memory, feedback loops, and how its work is evaluated.
Strands Agents lets you build a harness with tools, system prompts, plugins, specialized agents, context management, tracing, and evaluations. Claude Code is another example of a coding harness: it combines the model with repository instructions, file and terminal tools, permissions, MCP integrations, and automated workflows.
A better model can help, but a strong harness helps the model understand its environment, take the right actions, verify its work, and recover when something goes wrong.
