The manuscript contains an original and highly relevant conjecture supported by a substantial companion analysis. The requested revisions do not require expanding the letter into a full technical paper. They principally require sharpening the novelty claim, specifying the conventional status of the complexity normalization, limiting Lloyd-bound and dimensional statements to the regimes actually examined, and presenting charged hair as a proposed rather than demonstrated resolution.

This short letter proposes the complexity–action (CA) conjecture, C=A_WDW/(πℏ), identifying holographic state complexity with the on-shell action of the corresponding Wheeler–DeWitt patch. It presents late-time tests for neutral, rotating, and charged AdS black holes, together with perturbative tests involving static shells and shock waves. Its strongest result is the universal late-time neutral-black-hole rate dA/d(t_L+t_R)=2M, independent of horizon size and spacetime dimension.

The historical novelty is substantial but should be stated precisely. The general association between black-hole interior growth and complexity, the maximal-volume prescription, and the shock-wave/switchback benchmarks predate this manuscript [E2]. The new contribution is the replacement of maximal ERB volume by the action of the full WDW patch, eliminating the configuration-dependent auxiliary length scale and producing a universal late-time coefficient for neutral black holes [E1][E2].

The manuscript appropriately presents a conjecture supported by nontrivial semiclassical checks rather than claiming a derivation from boundary CFT complexity. The detailed action calculations delegated to [9] are present in the companion paper: they derive the arbitrary-dimensional neutral result, the four-dimensional charged result, the rotating BTZ result, static-shell time dilation, and single, multiple, finite-energy, and localized shock-wave behavior [E1].

The manuscript addresses a foundational problem in holography: how continuing black-hole interior growth may be encoded after ordinary boundary observables have equilibrated. The proposed relation connects quantum information, semiclassical gravity, tensor networks, and black-hole dynamics. The universal neutral result and the simpler treatment of shock-wave configurations make the proposal especially relevant.

The presentation is concise and generally effective for a short letter. Figures 1 and 2 clearly depict the relevant WDW patches for neutral/collapsing and charged geometries, respectively, and the progression from the conjecture to neutral, rotating, charged, shock-wave, and shell tests is coherent. The division of technical labor with the companion paper is legitimate, because that paper explicitly supplies the detailed derivations [E1].