SKM-D02 · Error
`description` is longer than 1024 characters
The specification caps `description` at 1024 characters.
What the rule is
The specification caps `description` at 1024 characters. This is the format's own ceiling — it's distinct from, and looser than, the tighter per-runtime budgets covered by SKM-P07 (OpenClaw's ~160-character guidance, Claude Code's practically-reported ~200).
A description this long is usually trying to do the job of the markdown body — enumerating steps or options — rather than stating a trigger condition.
Where it comes from
- Agent Skills — SpecificationSpecification / reference validator
- skills-ref validate (official reference validator, v0.1.5)Specification / reference validator
Strict spec conformance
Non-conformant. The official reference validator (skills-ref) rejects this — tested directly, not inferred from severity.
This is a separate question from the severity above and from which runtimes enforce it below — a rule can be a real, working extension in its home runtime while the reference validator still rejects the file outright, or vice versa. Both facts are reported, never one inferred from the other.
Which runtimes enforce it
| Runtime | Effect | Note |
|---|---|---|
| Claude Code | Not documented | The spec states the limit (confirmed: skills-ref hard-fails on this); no runtime documents what happens to a description that exceeds it (as distinct from the tighter runtime budgets below the spec ceiling — see SKM-P07). |
| Codex | Not documented | The spec states the limit (confirmed: skills-ref hard-fails on this); no runtime documents what happens to a description that exceeds it (as distinct from the tighter runtime budgets below the spec ceiling — see SKM-P07). |
| Cursor | Not documented | The spec states the limit (confirmed: skills-ref hard-fails on this); no runtime documents what happens to a description that exceeds it (as distinct from the tighter runtime budgets below the spec ceiling — see SKM-P07). |
| OpenClaw | Not documented | The spec states the limit (confirmed: skills-ref hard-fails on this); no runtime documents what happens to a description that exceeds it (as distinct from the tighter runtime budgets below the spec ceiling — see SKM-P07). |
| Hermes Agent | Not documented | The spec states the limit (confirmed: skills-ref hard-fails on this); no runtime documents what happens to a description that exceeds it (as distinct from the tighter runtime budgets below the spec ceiling — see SKM-P07). |
How to fix it
- Trim `description` to under 1024 characters. If it's carrying procedural detail, move that into the markdown body instead — the description only needs to state when the skill applies.
Elsewhere
- SKILL.md, the formatThe full frontmatter field table this rule is drawn from.
- Agent Skills Not WorkingThe diagnostic reference this rule’s portability and failure evidence comes from.
- All rulesEvery check the validator runs, grouped by class.