Conciseness

The body is ~110 lines of dense imperative bullets with zero concept explanation, no padding, and no over-explanation of things Claude already knows — e.g. 'Inventory version-like values without assuming the target Dart major or minor' followed immediately by copy-paste rg commands. Every line carries a non-obvious project-specific instruction, matching 'Lean and efficient; every token earns its place'.

Actionability

Concrete, copy-paste-ready rg commands, exact file paths (`.devcontainer/Dockerfile`, `.github/workflows/post_release.yaml`, `tools/frb_internal/...`), exact env var names (`FRB_MAIN_FLUTTER_VERSION`, `FRB_RUSTFMT_NIGHTLY_VERSION`), and a numbered 6-step validation order give mostly executable guidance. It is not fully self-contained executable, however: lint/test/generation commands are deferred to sibling skills (frb-lint, frb-test, frb-code-generation), which is appropriate routing but leaves minor gaps versus anchor 5's 'copy-paste ready code or commands' covering the common cases.

Workflow Clarity

Sections 1-9 form a coherent start-to-finish sequence (confirm target -> version contract -> PR boundaries -> toolchain -> CI pins -> regenerate -> validate -> triage -> PR notes) with explicit dependency checkpoints ('Complete the independent Docker predecessor ... before relying on the upgraded image', 'Before declaring it ready, run the independent review gate') and an error-recovery path in section 8 (triage in dependency order, compare against release notes before adding workarounds, route to frb-fix-ci). This matches anchor 5's 'Clear sequence with explicit validation steps; feedback loops for error recovery'.

Progressive Disclosure

No bundle files (references/, scripts/, assets/) exist; the body keeps itself to orchestration and consistently delegates detail to clearly named sibling skills at one level deep (frb-dev-env, frb-upgrade-docker, frb-code-generation, frb-pr-chain-split). Structure and signaling are good, matching anchor 4 'Good structure; most content is appropriately placed; references mostly clear'; it does not reach anchor 5 because some heavier inline material (the file inventory in section 2 and the validation ladder in section 7) could arguably live in a reference file, and there are no in-bundle reference files organizing the routing targets.

Specificity

The description names the domain ("flutter_rust_bridge", "Flutter stable release") and one concrete action ("Upgrade flutter_rust_bridge to a new Flutter stable release"), but lists no secondary actions like regenerating bindings or syncing CI pins. This matches the anchor 'Names domain and 1-2 concrete actions, but not comprehensive' and falls below anchor 4, which requires several specific actions.

Completeness

The 'what' is explicit ("Upgrade flutter_rust_bridge to a new Flutter stable release") and the 'when' is explicit with concrete trigger phrases ("Use when changing Flutter/Dart versions, devcontainer Docker images, CI/post-release pins..."). Both are clearly answered, matching anchor 5; anchor 4 would require the 'when' to be less explicit or specific, which is not the case.

Trigger Term Quality

Triggers such as "changing Flutter/Dart versions", "devcontainer Docker images", "CI/post-release pins", "generated Flutter scaffolds", and "platform compatibility" are phrases users would naturally say. A few natural variations are missing (e.g., 'upgrade Flutter', 'bump Flutter version', 'flutter_rust_bridge' itself), matching 'Good keyword coverage; a few natural terms missing' rather than the fully comprehensive anchor 5.

Distinctiveness Conflict Risk

"flutter_rust_bridge" plus its toolchain-specific triggers (devcontainer images, post-release pins, CargoKit-adjacent scaffolds) define a clear niche with minimal overlap against generic Flutter or Docker skills. This matches anchor 5, 'Clear niche with distinct triggers; minimal conflict risk'.