Parameter count

What it means

Parameter count measures the inputs declared by a callable. A high count can indicate a broad responsibility, an unstable interface, or a missing value object. It can also be appropriate for a low-level serialization or mathematical function. Interpret the count with call-site clarity and how often parameters change together.

Example

A constructor accepts twelve options, several booleans, and two callbacks. Replacing related values with named configuration objects may make invalid combinations harder to express and reviews easier to follow.

Limitations

Reducing the count by bundling unrelated values can hide coupling rather than remove it. Optional defaults and generated signatures also complicate comparisons. Favor domain clarity over an arbitrary maximum.

How to use the signal

Look for parameters that change together, but do not bundle unrelated values merely to satisfy a numeric threshold.

Weave can help compare parameter-heavy interface changes with review iteration and rework. The metric identifies candidates, while engineers decide whether a value object, builder, or simpler responsibility is appropriate.