Please describe the problem.

Current syntax of dead online at git annex dead [repository ...] [--key somekey ...] says

git annex dead [repository ...] [--key somekey ...]

which is also incorrect rendering I think since it is

[d31548v@ndoli tmp]$ git annex dead --help
git-annex dead - hide a lost repository or key

Usage: git-annex dead [[REPOSITORY ...] | [--key KEY]]

so it is EITHER to announce REPOSITORY or a KEY.

Naive/new/quick users, since many annex commands take file paths as arguments could provide dead with both - repository and local paths, e.g. git annex dead here */*.nii.gz or alike. But then annex proceeds with marking here dead while then erroring out on paths:

(datalad-dev) [d78092t@ndoli 1080_wasabi]$ git-annex dead here sub-SID000743/ses-01/func/*.nii
dead here (recording state in git...)
ok
git-annex: there is no available git remote named "sub-SID000743/ses-01/func/sub-SID000743_ses-01_task-hyperalignment_acq-mb8_run-04_bold.nii"

which is correct/expected behavior given the fact that if RTFM then those are to be taken as repositories.

But I wondered if may be git annex could/should become more "protective" and fail early if any of provided repositories is "not available"?