SKM-B02 · Warning
Body is around or over 5,000 tokens
The specification recommends keeping the activated body under roughly 5,000 tokens.
What the rule is
The specification's activation-stage guidance recommends staying under roughly 5,000 tokens for the body content that loads when a skill fires. This tool estimates tokens as characters divided by four — a rough approximation, not a real tokenizer result, since no tokenizer ships with this checker.
This measures the same underlying cost as SKM-B01 (line count) from a different angle — a file can pass one and fail the other depending on line length and content density.
Where it comes from
- Agent Skills — SpecificationSpecification / reference validator
- SKILL.md, the format hubSpecification / reference validator
- skills-ref validate (official reference validator, v0.1.5)Specification / reference validator
Strict spec conformance
Conformant. The official reference validator (skills-ref) accepts this.
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 basis as SKM-B01 — a real context cost inherent to the format's activation mechanism, but not a figure any of the five runtimes documents specifically. |
| Codex | Not documented | Same basis as SKM-B01 — a real context cost inherent to the format's activation mechanism, but not a figure any of the five runtimes documents specifically. |
| Cursor | Not documented | Same basis as SKM-B01 — a real context cost inherent to the format's activation mechanism, but not a figure any of the five runtimes documents specifically. |
| OpenClaw | Not documented | Same basis as SKM-B01 — a real context cost inherent to the format's activation mechanism, but not a figure any of the five runtimes documents specifically. |
| Hermes Agent | Not documented | Same basis as SKM-B01 — a real context cost inherent to the format's activation mechanism, but not a figure any of the five runtimes documents specifically. |
How to fix it
- Move detail out of the activated body and into `references/`, the same fix as SKM-B01. Treat the token estimate as directional, not exact.
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.