Conciseness

The ~30-line body is lean with zero padding: it states the purpose ("request provider-native context compaction for mounted CCB agents" — domain-specific knowledge, not something Claude already knows), three command examples, and five terse rules. Every token earns its place, matching anchor 5; there is nothing to trim that would push it to anchor 4.

Actionability

Three copy-paste-ready commands ("command ccb compact", "command ccb compact \"$AGENT\"", "command ccb compact agent1 agent2") cover the common cases of all-agents, single-agent, and multi-agent targeting, with the only placeholder being the standard $AGENT substitution. Behavior rules are concrete ("Run once, report the command output, and stop"), matching anchor 5.

Workflow Clarity

The single action is unambiguous with a documented pre-flight guard ("Busy or queued agents are blocked before any pane input is sent") and an explicit completion rule ("Run once, report the command output, and stop. Do not poll"), and the operation is explicitly non-destructive ("It does not delete .ccb state, workspaces, auth, sessions, logs, or memory files"), so the destructive/batch cap does not apply. It falls short of anchor 5 only because no guidance is given on what to do when an agent reports `unsupported` or is blocked — a minor validation/checkpoint gap.

Progressive Disclosure

The skill is under 50 lines with no need for external references, and the body is well organized into a purpose statement, a Commands section, and a Rules section. Per the rubric's simple-skill guidance this matches anchor 5; there are no buried references or inline content that belongs in separate files.

Specificity

Quotes "Compact CCB managed agent conversation context with `ccb compact`" — the domain and one concrete action are named via a specific command, but the description does not list several distinct actions. It fits anchor 3 (domain + 1-2 concrete actions, not comprehensive) rather than 4, and is clearly above anchor 2's generic-action level.

Completeness

The what is explicit ("Compact CCB managed agent conversation context with `ccb compact`") and the when is fully explicit ("Use when the user writes $ccb-compact, $ccb_compact, or asks to summarize one or more mounted agent contexts…") with concrete trigger phrases, matching anchor 5. It exceeds anchor 4 because the when-clause needs no further specificity.

Trigger Term Quality

Triggers include both spelling variants "$ccb-compact", "$ccb_compact" and the natural phrase "asks to summarize one or more mounted agent contexts without restarting agents or deleting project state". Good keyword coverage for the niche, but natural synonyms like "condense", "trim", or "clean up context" are missing, so it matches anchor 4 rather than 5.

Distinctiveness Conflict Risk

Triggers are CCB-specific ("$ccb-compact", "$ccb_compact", "mounted agent contexts") creating a clear niche with minimal overlap risk against generic summarization or compaction skills. This matches anchor 5; anchor 4's 'minor overlap risk' would apply if generic terms like bare 'summarize' were the primary trigger.