← Reddit

Opus 5 is just.. profoundly broken

Reddit · damndatassdoh · August 5, 2026
A user reconfigured their Claude setup based on Anthropic's blog recommendations for Opus 5 and initially observed promising results. However, the model frequently produced false positives, engaged in shallow analysis, and leaped to incorrect conclusions without recognizing flawed premises despite multiple reviews and planning cycles. The user characterized the model as inefficiently using tokens while producing minimal output.

Detailed Analysis

A Reddit post titled "Opus 5 is just... profoundly broken," published to r/Anthropic, offers a sharply critical firsthand account of Claude Opus 5 in production use. The author describes following Anthropic's own guidance by reworking their CLAUDE.md configuration file to better align with the new model's expected behavior, only to encounter what they characterize as systemic reliability failures. Central to the complaint is a pattern of false positives: the model allegedly identifies problems that do not exist, then proceeds through multiple rounds of planning and review without ever revisiting or questioning the flawed initial premise. The author's framing—"a perfect token burning model, geared to produce minimal results from maximal effort"—suggests a workflow where computational cost and apparent diligence (repeated planning cycles) are decoupled from actual task-relevant accuracy.

This complaint touches on a well-known failure mode in large language model agents: premise-locking, where a model commits early to an incorrect assumption and then reasons confidently and elaborately within that flawed frame rather than stepping back to re-examine it. This is distinct from simple hallucination; it is a failure of self-correction and metacognitive checking during extended, multi-step reasoning or agentic workflows. For coding and technical-review use cases—where CLAUDE.md files are typically used to give Claude persistent project context and behavioral instructions—this kind of error is especially costly, since developers may not immediately notice that hours of "review" happened downstream of a mistaken diagnosis. The user's framing of the issue as "shallow reads" leading to confidently wrong conclusions echoes broader concerns raised by developers about agentic coding assistants prioritizing the appearance of thoroughness (multiple planning passes, verbose intermediate steps) over grounded correctness.

The complaint also matters because it comes at a moment when Anthropic has been pushing Claude models, including recent Opus releases, toward more autonomous, multi-step agentic behavior—longer planning chains, tool use, and self-directed task execution—rather than single-turn question answering. When a company explicitly instructs users to adapt configuration files to accommodate a new model's behavior, as this poster describes doing, it signals that model updates can meaningfully change how the system should be prompted and scaffolded. If that adaptation instead surfaces new failure modes rather than resolving old ones, it raises legitimate questions about whether increased agentic capability (more autonomous planning, more tool calls, longer chains of reasoning) is being matched by proportional improvements in judgment, self-verification, and error recovery.

More broadly, this kind of user report reflects a recurring tension in the frontier AI model release cycle: benchmark performance and headline capability claims do not always translate cleanly into reliable, cost-effective real-world performance, particularly in long-horizon agentic tasks. "Token burning" complaints—where a model consumes substantial compute performing seemingly rigorous work that fails to converge on correct outcomes—have become a common critique across multiple AI labs' most capable models, not unique to Anthropic. Such anecdotal, single-user complaints on forums like Reddit are not definitive evidence of systemic model regression, but they contribute to the broader, crowdsourced feedback loop through which practitioners evaluate whether new "flagship" models represent genuine improvements in reasoning quality or merely shifts in style, verbosity, and apparent effort that outstrip real correctness gains.

Read original article →