AI Coders Write Code, But Do They Understand Logging?

Author: Denis Avetisyan


A new study reveals that while AI coding agents can produce functional code, they often fall short when it comes to crucial observability practices like detailed logging.

The study characterizes agentic logging through a novel approach, establishing a framework for understanding and quantifying the properties of autonomous record-keeping systems and their inherent behaviors.
The study characterizes agentic logging through a novel approach, establishing a framework for understanding and quantifying the properties of autonomous record-keeping systems and their inherent behaviors.

Researchers found AI-generated code frequently lacks sufficient logging, ignores explicit logging requests, and requires substantial human effort to achieve adequate software observability.

While software logging is crucial for system maintainability, its implementation by increasingly prevalent AI coding agents remains largely unexamined. This study, ‘Do AI Coding Agents Log Like Humans? An Empirical Study’, empirically investigates logging practices across 4,550 agentic pull requests, revealing that agents often exhibit lower logging frequency compared to human developers, despite generating denser logs when they do. Notably, explicit logging instructions are scarce and frequently ignored, leading to substantial human intervention in correcting logging deficiencies post-generation. These findings suggest a critical gap in aligning agent behavior with essential non-functional requirements-and raise the question of whether deterministic guardrails are necessary to ensure reliable observability in AI-generated code.


The Fundamental Limits of Observability

Effective software observability represents a fundamental shift in how systems are managed, moving beyond simple monitoring to a deep understanding of a system’s internal state. This isn’t merely about tracking whether a service is up or down; it’s about knowing why it behaves as it does, even in complex, distributed architectures. Such insight is increasingly crucial for ensuring reliability, as organizations demand consistently high performance and rapid issue resolution. Without observability, identifying the root cause of performance bottlenecks or failures becomes a protracted and often inaccurate process, directly impacting user experience and potentially leading to significant financial losses. The ability to actively query and analyze internal data-traces, metrics, and logs-provides the granular detail necessary to proactively address issues, optimize performance, and accelerate innovation.

Historically, software developers have depended on manually inserted logging statements to trace execution and diagnose issues; however, this practice introduces significant limitations in modern systems. As codebases grow in size and complexity – encompassing microservices, distributed systems, and asynchronous operations – the sheer volume of potential log statements becomes unmanageable, leading to inconsistent implementation across teams and incomplete coverage of critical code paths. This reliance on manual logging creates observability gaps, where crucial runtime information is simply not captured, hindering the ability to effectively monitor application health, pinpoint performance bottlenecks, and rapidly resolve incidents. The inherent human error and scalability challenges of manual logging are increasingly insufficient for maintaining reliable and performant software in today’s dynamic environments.

Agentic and human pull requests undergo a post-generation logging revision flow to ensure quality and track modifications.
Agentic and human pull requests undergo a post-generation logging revision flow to ensure quality and track modifications.

Automating Insight: The Potential of AI Agents

AI coding agents leverage Large Language Models (LLMs) to automate aspects of software logging previously requiring manual implementation. These agents function by analyzing existing codebases and, based on identified patterns and contextual understanding, generating relevant logging statements. The automation potential extends to various logging levels – debug, info, warning, error – and can be applied to new code development or retrofitted to existing systems. LLMs are trained on vast datasets of code, enabling them to suggest logging statements that align with established coding practices and common software architectures. This approach aims to reduce the time and effort associated with implementing comprehensive logging, thereby improving software observability and debugging capabilities.

AI coding agents leverage Large Language Models to autonomously produce functional code, inclusive of logging statements, with reduced reliance on manual developer input. This capability facilitates the automated insertion of logging throughout a codebase, potentially expanding logging coverage to areas frequently overlooked or inconsistently addressed. The agents can be prompted with high-level requirements or existing code context to generate relevant logging statements, and their iterative refinement capabilities allow for adjustments based on feedback or testing. This automated approach aims to standardize logging practices, reduce human error in statement creation, and improve the overall consistency of log data across a software system.

The automated generation of logging statements by AI coding agents must be coupled with quality control mechanisms to avoid introducing irrelevant or misleading data. High volumes of low-value logs can obscure critical information, increase storage costs, and degrade application performance. Effective logging requires statements that capture meaningful events, include sufficient context for debugging, and adhere to established logging standards. Therefore, post-generation analysis – including static analysis, automated testing, and potentially human review – is crucial to validate the usefulness and accuracy of AI-generated logging code before deployment.

Agentic pull requests exhibit a strong correlation between pull request size and the number of post-generation logging revisions, mirroring the trend observed in human-authored pull requests.
Agentic pull requests exhibit a strong correlation between pull request size and the number of post-generation logging revisions, mirroring the trend observed in human-authored pull requests.

Validating Agentic Logging: A Rigorous Examination

Post-generation logging regulation, encompassing the review and correction of logging statements, remains a critical quality assurance step despite the increasing use of AI-driven code generation. This process ensures the accuracy, consistency, and utility of log data for debugging, monitoring, and auditing purposes. While AI agents are capable of generating logging statements, current research indicates substantial human involvement in correcting them. Effective regulation involves verifying that logs adhere to established coding standards, accurately reflect the code’s behavior, and provide sufficient context for effective troubleshooting. Neglecting this post-generation review can lead to inaccurate or incomplete logs, hindering the ability to diagnose and resolve issues in production systems.

Static analysis tools and Continuous Integration/Continuous Delivery (CI/CD) pipelines are vital for regulating agentic logging by automating the enforcement of logging standards and consistency. These systems can be configured to scan pull requests for deviations from established logging formats, missing log statements in critical code paths, and potentially sensitive information being logged. Automated checks within CI/CD pipelines can flag non-compliant changes, preventing them from being merged into the codebase. This proactive approach reduces the burden of manual review and ensures that logging practices remain uniform and maintainable across the project, regardless of whether changes originate from human developers or AI agents.

Analysis of post-generation logging repairs indicates substantial human involvement, with humans responsible for 72.5% of all corrections. Comparative data across 58.4% of repositories shows agents modify logging statements less frequently than human developers. A significant contributing factor appears to be insufficient direction; only 4.7% of pull requests originating from agents include explicit logging instructions. These findings suggest current agentic logging practices require increased guidance and improved proactive behavior to reduce reliance on manual intervention and enhance logging quality.

Logging Prevalence and Log Density serve as quantifiable metrics for evaluating logging behavior in code repositories. Logging Prevalence is calculated as the percentage of pull requests that include at least one logging statement, indicating the frequency with which developers incorporate logging into their changes. Log Density, conversely, measures the average number of logging statements per line of code modified within a pull request, reflecting the granularity of logging detail. Comparative analysis of these metrics between Human PRs and Agentic PRs allows for the identification of discrepancies in logging practices; for example, lower Log Density in Agentic PRs may suggest a need for improved guidance on generating more informative logs, while differences in Logging Prevalence can reveal variations in the adoption of logging practices between human developers and AI agents.

A comparison of logging frequency between human-authored and agent-generated pull requests reveals distinct repository-level distributions and paired differences in logging prevalence.
A comparison of logging frequency between human-authored and agent-generated pull requests reveals distinct repository-level distributions and paired differences in logging prevalence.

Towards Intelligent Logging: A Paradigm Shift

The development of intelligent logging systems is increasingly leveraging the capabilities of reinforcement learning to train AI coding agents. This approach moves beyond simple rule-based logging by allowing agents to learn, through trial and error, which logging statements are most valuable in debugging and monitoring software. Verifiable rewards, automatically assigned based on the logging statement’s impact on tasks like fault localization, provide a direct signal for improvement. Further refinement comes through human feedback, where developers evaluate the quality of generated logs, guiding the agent towards logging practices that mirror expert behavior. This iterative process of reward and feedback enables agents to autonomously generate high-quality logging statements, ultimately reducing the manual effort required for effective software maintenance and enhancing system observability.

The efficacy of AI coding agents hinges on their ability to produce logging statements that genuinely aid debugging and system understanding; therefore, a crucial advancement lies in shaping agent behavior through targeted feedback. Rather than simply mimicking human logging patterns, these agents can be trained to prioritize informative statements by receiving clear signals regarding the quality of their output. This is achieved through reinforcement learning, where agents are rewarded for generating logs that demonstrably improve code comprehension – for example, logs that quickly pinpoint the source of an error or effectively track critical system events. By associating specific logging practices with positive reinforcement, agents learn to move beyond boilerplate and focus on producing logs that are genuinely useful, ultimately reducing the burden on human developers and fostering more maintainable software.

The capacity of AI coding agents to generate effective logging statements is significantly influenced by explicit direction, delivered through repository instruction files and issue descriptions. These resources serve as guidelines, shaping the agent’s logging behavior by communicating specific requirements or desired outcomes. However, current performance reveals a substantial gap in instruction following, with agents failing to comply with these logging requests in 67% of cases. This suggests a critical need for improvements in how agents interpret and execute instructions, highlighting a key area for research and development in intelligent logging systems. Addressing this compliance issue is crucial for realizing the full potential of AI-driven logging, moving beyond mere mimicry of human practices towards truly autonomous and reliable log generation.

Despite advancements in AI coding agents capable of generating logging statements, substantial human intervention remains critical for maintaining code quality. Research indicates that humans currently perform 72.5% of all post-generation repairs to these automatically created logs. This suggests that while agents effectively mimic human logging practices – incorporating mechanics like statement structure and common patterns – they struggle with contextual relevance and accurate information capture. The high rate of human repair underscores a current limitation in the agent’s ability to independently produce logs that are both functionally correct and genuinely useful for debugging and system monitoring. This necessitates ongoing human oversight, highlighting a key area for future development in intelligent logging systems focused on improving the agent’s capacity for nuanced understanding and accurate log generation.

Analysis of 57 repositories reveals that pull request log messages generated by an agent are comparable in length to those written by humans, as shown by distributions across repositories and paired per-repository median comparisons.
Analysis of 57 repositories reveals that pull request log messages generated by an agent are comparable in length to those written by humans, as shown by distributions across repositories and paired per-repository median comparisons.

The study highlights a critical divergence between AI-generated code and human-authored software regarding observability. While agents can produce syntactically correct logging statements, they frequently fail to anticipate future debugging needs or adhere to nuanced logging directives. This echoes Ada Lovelace’s sentiment: “That brain of mine is something more than merely mortal; as time will show.” The ‘mortal’ code produced lacks the foresight-the analytical engine’s capacity for anticipating complex states-that a skilled programmer inherently possesses. The observed need for substantial human intervention isn’t merely about fixing errors; it’s about imbuing the code with a logical structure and predictive capability-qualities that define true algorithmic elegance, not just functional output.

Future Directions

The observed deficiencies in automated logging are not merely practical concerns; they expose a fundamental mismatch between the current paradigm of large language model-driven code generation and the principles of deterministic software engineering. The capacity to produce syntactically correct code, even code that passes initial tests, is distinct from the capacity to produce code that is inherently knowable. Observability, achieved through rigorous logging, is not an afterthought – it is a prerequisite for reliable systems. The study highlights that current agents struggle to consistently integrate this principle.

Future research must move beyond evaluating superficial logging patterns. The focus should shift to formally verifying the completeness and correctness of generated logging statements. Can agents be compelled, through formal specifications, to generate code demonstrably capable of reproducing any internal state? The current reliance on empirical observation-does it log ‘enough’?-is insufficient. A provable logging strategy, tied to the underlying algorithm, is the only acceptable standard.

The implications extend beyond mere debugging. In safety-critical systems, the ability to reconstruct execution history is paramount. If the provenance of a result cannot be definitively established, the system is, by definition, untrustworthy. The field requires a move towards agents that prioritize mathematical rigor over statistical mimicry. Only then will generated code transcend the realm of approximation and approach the ideal of provable correctness.


Original article: https://arxiv.org/pdf/2604.09409.pdf

Contact the author: https://www.linkedin.com/in/avetisyan/

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2026-04-13 18:15