Understanding how a coding agent works makes its failures much easier to diagnose.
The basic loop
The agent receives a task and then repeats a cycle: form a plan, choose a tool, call it, observe the result, and decide what to do next. Typical tools include reading files, searching the repository, editing files, and running shell commands such as Gradle tasks.
Tool schemas matter
Each tool is described to the model by a schema that defines its name and arguments. If the agent produces malformed arguments, the runtime should report a clear error so the agent can correct itself. Vague or overly broad tools lead to unpredictable behavior.
Context is the agent's working memory
Everything the agent has read and done must fit in its context window. As sessions grow, older material is summarized or dropped. Important details can be lost, which sometimes explains why an agent "forgets" an earlier instruction.
Common failure patterns
- Looping: repeating the same failing command.
- Drifting: wandering away from the original task.
- Overreaching: editing files it was not asked to touch.
- Premature success: declaring victory without running checks.
What to do about them
Give the agent small, well-defined tasks. Provide fast verification steps such as a quick unit-test or lint command. Review transcripts like logs to see where the agent went wrong.
Result
A bounded loop with clear tools and quick feedback is far more reliable than an open-ended one.
Continue with the book
Explore the full treatment, worked examples, and exercises in Agentic Android App Development.
Adapted from Agentic Android App Development, published by Choral Software. Article text and original examples © 2026 Choral Software. All rights reserved.