SKM-D03 · Error
`description` is empty
An empty description can't do the job of triggering the skill in any runtime.
What the rule is
The `description` field is present in the frontmatter but its value is an empty string. Functionally this is the same failure as a missing description (SKM-D01): the field an agent uses to decide whether the skill is relevant carries nothing to match against.
This usually happens when a template's placeholder value was deleted but the field itself was left in.
Where it comes from
- Agent Skills — SpecificationSpecification / reference validator
- Agent skills not workingAgentSkills.site
- Agent Skills — Adding skills support to your agent (client-implementation guide)Specification / 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 | Same evidentiary basis as SKM-D01 — the client-implementation guide recommends skipping the skill and skills-ref hard-fails this, but neither names a specific runtime's actual behavior. |
| Codex | Not documented | Same evidentiary basis as SKM-D01 — the client-implementation guide recommends skipping the skill and skills-ref hard-fails this, but neither names a specific runtime's actual behavior. |
| Cursor | Not documented | Same evidentiary basis as SKM-D01 — the client-implementation guide recommends skipping the skill and skills-ref hard-fails this, but neither names a specific runtime's actual behavior. |
| OpenClaw | Not documented | Same evidentiary basis as SKM-D01 — the client-implementation guide recommends skipping the skill and skills-ref hard-fails this, but neither names a specific runtime's actual behavior. |
| Hermes Agent | Not documented | Same evidentiary basis as SKM-D01 — the client-implementation guide recommends skipping the skill and skills-ref hard-fails this, but neither names a specific runtime's actual behavior. |
How to fix it
- Write a real description — a trigger-focused sentence stating when the skill should be used, not a placeholder.
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.