> ## Documentation Index > Fetch the complete documentation index at: https://docs.comet.rpamis.com/llms.txt > Use this file to discover all available pages before exploring further. # Runtime Check (Advanced) > Distinguish comet eval and comet skill check, understand the local completeness check of a specific Skill run, the checks.yaml format, and pending action recovery. This is advanced content, mainly for advanced users who need to debug Skill runs (Engine Runs). If you only do `comet eval` (authoring-time evaluation), you can skip this page. Comet has two types of eval. Their names are similar but their purposes are different — **don't mix them**. ## Comparison | Command | What it evaluates | Question it's suited for | Is it publish evidence? | Which file it reads | | ------------------- | --------------------------------- | ---------------------------------------------- | ----------------------- | ------------------- | | `comet eval` | Skill bundle or `comet/eval.yaml` | Can this Skill pass a product-level evaluation | **Yes** | `comet/eval.yaml` | | `comet skill check` | A specific Skill run | Is this run missing artifacts or state | No | `comet/checks.yaml` |

Little fish separating comet eval's publish evidence and comet skill check's run-completeness check onto two workbenches

comet eval produces publish evidence; comet skill check only checks whether a specific Skill run is complete

## Why Two Types `comet eval` is aimed at "can this Skill, as a product capability, pass the evaluation". It executes real model tasks through a shared eval harness and produces pre-release evidence. `comet skill check` is aimed at "is this Skill run complete". It only checks whether the current run satisfies the runtime checks in `comet/checks.yaml`, **executing no model tasks** and **producing no publish evidence**. The two serve different stages: `comet skill check` checks completeness during a Skill run, while `comet eval` verifies product capability before release. ## Runtime Check Format Runtime checks are defined in the Skill bundle's `comet/checks.yaml` (or `comet/evals.yaml` — choose one of the two; they cannot coexist). `/comet-any` artifacts default to `checks.yaml`. ```yaml theme={null} # comet/checks.yaml runtime: - id: completed scope: completion type: state_equals field: status equals: completed ``` Fields of each runtime check: | Field | Description | | ------------------ | -------------------------------------------------------------------------------------------- | | `id` | Check identifier | | `scope` | `progress` (on demand) / `step` (after each outcome) / `completion` (when the Run completes) | | `type` | `artifact_exists` or `state_equals` | | `artifact` | The artifact key to check when `artifact_exists` | | `field` / `equals` | When `state_equals`, checks whether the Run state field equals the specified value | ### Two Check Types | Type | How it judges | | ----------------- | -------------------------------------------------------- | | `artifact_exists` | The corresponding artifact exists in the artifacts store | | `state_equals` | A field of the Run state equals the specified value | ### Three Scopes | scope | When it runs | Trigger | | ------------ | ------------------------------------------------------ | ------------------------------------ | | `step` | Runs automatically after each submitted action outcome | Automatic | | `completion` | Runs automatically when the Run reaches completed | Automatic | | `progress` | Runs on demand | `comet skill check --scope progress` | ## comet skill check Example Runtime checks are typically used together with `comet skill run` and `comet skill continue`: ```bash theme={null} # Start a Skill run comet skill run my-skill --run-id demo-run --project . # The Agent executes the pending action, then submits the result with resume comet skill continue --run-id demo-run --status succeeded --summary "Done" # Check the completeness of this Skill run comet skill check --run-id demo-run --scope completion --json ``` You can also bind an OpenSpec change directory: ```bash theme={null} comet skill run my-skill --change ./changes/demo comet skill continue --change ./changes/demo --status succeeded --summary "Done" --artifact report=report.md comet skill check --change ./changes/demo --scope completion ``` A Run can bind a `--change` directory, or use `--run-id` to place it under `.comet/runs/`. `run` supports deterministic Skills; adaptive execution requires Agent candidates. ## When You Need Runtime Checks Skill runs (Engine Runs) typically appear in these scenarios: * The Skill has multi-step state. * It needs pending action and resume. * It needs to check whether an artifact exists. * It needs guardrails or recovery semantics. * The Skill is Engine-enabled (`/comet-any` enables Engine by default for multi-step or high-risk artifacts). Engine-enabled artifacts write `comet/checks.yaml` and `comet/eval.yaml`: * `comet/checks.yaml`: runtime checks, used by `comet skill check`. * `comet/eval.yaml`: eval manifest, used by `comet eval`. ## Text-Mode Recovery Prompts In text mode, `comet skill` prints `Pending action` and `Next:` recovery prompts directly, so you don't have to guess the next step yourself after a paused Run or a failed check. For example, `run` output: ```text theme={null} Run: demo-run Status: paused Current step: collect-evidence Pending action: collect-evidence (tool, step collect-evidence) Runtime checks: 1 Next: complete the pending action, then run comet skill continue ``` When a check fails it prompts: ```text theme={null} Next: record the missing artifact/state and rerun comet skill check ``` Each `PASS`/`FAIL` carries evidence, e.g. `PASS completed: state.status = completed` or `FAIL report-exists: artifact report(missing) not found`. ## How to Choose * Your question is "can this Skill, as a product capability, pass the evaluation": ```bash theme={null} comet eval ./generated-skill/comet/eval.yaml --html ``` * Your question is "is this Skill run missing artifacts or state": ```bash theme={null} comet skill check --run-id --scope completion ``` When preparing to publish a Skill, do not only run comet skill check. Publish readiness requires the general comet eval evidence. comet skill check only checks the completeness of a specific Skill run; it is not a general Skill evaluation. ## Next steps * [comet skill command](/en/cli/skill) — complete Skill bundle and Run tool reference * [comet eval command](/en/cli/eval) — complete evaluation options * [Skill and Engine (Advanced)](/en/skill-creator/engine) — understand Skill Run (Engine Run) semantics, pending action, immutable snapshots