Conciseness

The body avoids explaining concepts Claude already knows and delivers largely non-obvious domain guidance, but includes notable redundancy: the Guidelines section restates Detailed Topics points, approach-selection guidance appears in both 'Core Concepts' and 'Select the Right Approach for the Session Profile', and the Integration and References sections both enumerate sibling skills. Mostly efficient but could be tightened — anchor 3, not 2 since no section is pure padding or known-concept explanation.

Actionability

Provides a copy-paste-ready structured summary template, a five-step anchored iterative summarization procedure, decision tables (trigger strategies, compression ratios, probe types), and explicit selection criteria per session profile. Falls short of anchor 5 because some guidance remains abstract — e.g., 'Implement a separate artifact index or explicit file-state tracking in agent scaffolding' offers no concrete example of what that looks like.

Workflow Clarity

The three-phase compression workflow and step-by-step anchored summarization are clearly sequenced, and validation guidance exists ('Always validate compressed output against source material before discarding originals', probe-based evaluation). Anchor 4 rather than 5 because validation is described as a separate practice rather than embedded as explicit checkpoints inside the step sequences (e.g., the five-step anchored summarization procedure has no validate step).

Progressive Disclosure

Sections are well organized and the one reference file (./references/evaluation-framework.md) is clearly signaled with 'Read when' guidance, one level deep. Not anchor 5 because the bundle's scripts/compression_evaluator.py (a substantial script in the skill directory) is never referenced anywhere in the body — a navigation gap; above anchor 3 since what is referenced is well signaled and content placement is generally appropriate.

Specificity

Lists multiple concrete capability areas — "context compression, structured summarization, compaction, token-per-task optimization, or durable handoff summaries that preserve decisions, files, risks, and next actions" — with only minor coverage gaps. Falls short of anchor 5 because capabilities are framed as session needs ('should be used when ... need X') rather than explicit actions the skill performs.

Completeness

The 'when' is explicit and concrete ("when long-running agent sessions need context compression, structured summarization, compaction..."), but the 'what' is only implied through the needs list rather than stated as what the skill does. That matches anchor 4 — both present, one less explicit — rather than anchor 5's fully explicit what-and-when.

Trigger Term Quality

Good keyword coverage with natural synonyms users would say: "context compression", "compaction", "structured summarization", "durable handoff summaries", "long-running agent sessions". Not anchor 5 because common variations like "context window limits" or "session summary" are missing; clearly above anchor 3's 'some relevant keywords'.

Distinctiveness Conflict Risk

The core niche (compression/compaction of long-running sessions) is fairly distinct, but secondary triggers "token-per-task optimization" and "durable handoff summaries" overlap with sibling skills the body itself disclaims (context-optimization, memory-systems), and the description carries no boundary guidance. Somewhat specific yet overlapping — anchor 3, not 4, because two of five triggers risk firing the wrong skill.