Rules for a calling agent:

Decide first (video-production-agent): which operation, which LUT, which tonemap curve, which retag target. This skill has no defaults for creative parameters that matter (LUT path, retag target) and never guesses which colour treatment to apply.
Give explicit, typed parameters: HDR_TO_SDR needs nothing but has typed tonemap/peak_nits/desat/force (without tonemap the curve follows the input's transfer: mobius for HLG, hable for PQ and anything else, ADR-28); LUT_APPLY needs lut_path; RETAG needs target; PRIMARY_CORRECTION needs nothing but has typed exposure/contrast/saturation/temperature/tint/gamma/lift/gain/levels_in_black/ levels_in_white/levels_out_black/levels_out_white/curves, each independently optional and defaulting to unchanged (curves defaults to no preset); OCIO_TRANSFORM needs source_space and either destination_space or display + view (names from the config), optional config/look/lut_size/output_tags; MATCH_CAMERA needs reference_path (camera A), with at/reference_at, model, optional patches, lut_size. Tone-mapping curve and correction values are always the caller's, never automatic.
Never send commands, argv, filter strings or executable paths: the request is rejected. A LUT path is data, resolved through its own path policy and hashed into provenance; it is never a filter string.
Keep outputs inside the workspace, never at the input path; set overwrite: true deliberately. An output's container must match the source's (this skill does not convert containers; that is ffmpeg-skill/export).
Read results[].status, outputs[].provenance and error from the JSON; the exit code is 0 only when ok is true.
An alpha source (ProRes 4444, qtrle, PNG) keeps its alpha through LUT_APPLY / PRIMARY_CORRECTION when ffmpeg-skill has --keep-alpha; other re-encoding operations refuse it (alpha_not_preserved). Say how its colour is stored with project.source.alpha_mode: straight | premultiplied (unsaid: PNG is straight, anything else is taken as straight with a warning). A premultiplied source is refused for those grades (alpha_premultiplied: ffmpeg-skill cannot un-premultiply it). project.source.drop_alpha: true asks for an opaque result instead (ADR-33).

See README.md for the schemas, operation table, error codes and limitations.

color-grading

color-grading