Claude Opus 5.5: reserve the model for tasks that justify it

Anthropic's press release presents Opus 5.5 as suitable for programming and knowledge work, with quality and cost comparisons to its previous models. These results come from the evaluations and conditions described by the supplier.

They do not directly predict the performance of a particular process. Daillac has not replicated these benchmarks. Pricing, versions, limits and availability conditions should be checked at the time of integration, especially if a new version is announced between writing and publication.

A repetitive extraction of a few fields does not have the same structure as an analysis of several conflicting documents. A complex task may have to resolve dependencies, formulate hypotheses, or explain the limitations of a conclusion. It may also require a series of tools whose results must be compared.

Business risk is another dimension. A response to prepare a draft does not have the same effect as a proposal used to decide on a migration. A successful model can help to examine the options, but the responsibility for the decision and its validation remains defined by the organization.

This map does not automatically assign a model to each category. It allows you to prepare tests and compare capabilities against the cost of the accepted result. A simple process can become difficult if the data is inconsistent or if the system calls the wrong tools.

An architecture may reserve a more demanding model for cases requiring deeper analysis. Define the signs that trigger this transition: conflicting information, a decision that needs justification, or an uncovered exception. Also test the errors of this routing rule.

A case misclassified as simple may produce an incorrect response; a case unnecessarily escalated may increase the cost. Keep track of the reason for the choice and check if the user can request a review. Expected savings must be measured on the complete system.

The RAG framework, fine-tuning, and custom model reminds us that the choice of model is only one decision among others. Better organized sources and a better defined task can have more effect than a change in capacity alone.

A long run must have a budget, a timeline, and stopping criteria. The agent must be able to report an unavailable tool or an unverified assumption. A plausible final result is not sufficient if the necessary steps have not been completed.

Permissions must remain tied to the task. An architecture scan can look at documents without being given the right to deploy. A development assistant can prepare a change without deciding on its own to put it into production. The AI implementation must make these boundaries explicit.

Decisive evidence relates to the allocation rule. Examine cases sent unnecessarily to a more costly model, complex cases that stayed in the current workflow, and cases that still require a person. These three groups explain the architecture better than a single average score.

A adapted AI architecture defines the escalation threshold, the elements transmitted from one step to the next, and the person responsible for exceptions. Daillac did not test Opus 5.5 for this text; the rules described are proposals for analysis, to be compared with your files.

Example of a mock rule: a structured drillthrough remains in the current path; a folder containing two conflicting documents is reviewed; a multi-step analysis can be assigned to a more expensive model after ranking. Escalation should not depend solely on the model's stated trust. Use observable signals—contradiction, missing part, business exception—and examine classification errors. The topic of this analysis is the division of tasks, rather than migrating the entire application to a single model.

Anthropic — Introducing Claude Opus 5.5. Sources consulted on October 1, 2026; the grids and sample decisions are an editorial analysis by Daillac.