California State University, San Marcos

On the 244 free-form tasks of PromptBio-Bench, Claude Opus 5.5 running in Claude Code completed every task and reached 0.869 accuracy under the original evaluation framework, against 0.758 for Biomni and ToolsGenie and 0.717 for STELLA. With 667 bioinformatics Agent Skills installed, the agent never invoked a skill in 444 subagent sessions; after evaluator defects were fixed, the skills configuration reached 0.918 under a GPT judge and 0.926 under a Claude judge, while the no-skills configuration reached 0.873 and 0.902. Of the 18 remaining failures, 7 trace to defective references and 4 to settings the tasks never state.

On the 244 free-form tasks of PromptBio-Bench, Claude Opus 5.5 running in Claude Code completed every task and reached 0.869 accuracy under the original evaluation framework, against 0.758 for Biomni and ToolsGenie and 0.717 for STELLA. With 667 bioinformatics Agent Skills installed, the agent never invoked a skill in 444 subagent sessions; after evaluator defects were fixed, the skills configuration reached 0.918 under a GPT judge and 0.926 under a Claude judge, while the no-skills configuration reached 0.873 and 0.902. Of the 18 remaining failures, 7 trace to defective references and 4 to settings the tasks never state.