Conciseness

Mostly efficient tactical content, but Core Concepts restates Detailed Topics (the 70% compaction trigger and each strategy's summary appear twice), and it explains fundamentals Claude already knows ("KV-cache stores Key and Value tensors computed during inference..."), plus a metadata block with version dates. Matches 'mostly efficient but includes some unnecessary explanation or could be tightened'. Not 2: the bulk is genuinely additive, non-padded guidance.

Actionability

Highly concrete guidance: specific thresholds (70%/80% triggers, 50-70% reduction, <5% degradation), a decision-framework table, byte-level cache-stability rules, and specific gotcha mitigations ("suspend masking for all error-related observations", "batch such edits"). Not 5: the code examples call undefined functions (compact_context, store_observation, extract_key) — illustrative pseudocode rather than executable code.

Workflow Clarity

Full explicit workflow with validation and feedback loops: "Measure before optimizing, then measure the optimization's effect"; a decision-framework table for technique selection; a priority order; tracked performance targets; and "If an optimization technique does not measurably improve the target metric, remove it" — plus error-recovery audits ("audit the summary for critical information loss", "re-validate the summary against the current task goal") and an 8-item checklist. Matches the top anchor; not 4: validation checkpoints are explicit at every stage, not just most.

Progressive Disclosure

Good sectioning and one clearly signaled one-level reference (./references/optimization_techniques.md with an explicit 'Read when' clause), but the bundle's scripts/compaction.py (19KB) is never referenced from the body — an orphaned, unnavigable file — and 'External resources' are unnamed topic labels rather than actual links. Significant detail (thresholds, per-message-type preservation rules) is inlined that belongs in the reference file. Matches 'some structure but could be better organized; references present but not clearly signaled' in spirit via the navigation gap. Not 4: the orphaned script and placeholder external resources are more than minor organization gaps.

Specificity

Enumerates seven concrete capability areas ("context budgeting, observation masking, prefix or KV-cache strategy, partitioning, token-cost reduction, retrieval scoping"), matching 'lists several specific actions; minor gaps'. Not 5: terms remain jargon-abstract and omit core mechanisms the body covers (e.g., compaction/summarization). Not 3: coverage clearly exceeds 1-2 actions.

Completeness

Explicit 'what' (the enumerated capability list) plus an explicit trigger clause ("This skill should be used for improving context efficiency"), so the missing-trigger cap at 3 does not apply. Not 5: the 'when' is folded into the 'what' sentence and lacks concrete user-facing trigger phrases (e.g., 'Use when the user mentions...'), matching 'when could be more explicit or specific'.

Trigger Term Quality

Some relevant natural terms ("context", "token-cost", "KV-cache") but insider phrasing dominates ("observation masking", "retrieval scoping", "partitioning") while common user phrasings like "context window", "reduce token usage", or "summarize conversation history" are missing. Matches 'some relevant keywords but missing common variations or synonyms', not 4 which requires broader natural-term coverage.

Distinctiveness Conflict Risk

Clear niche with distinct technical triggers, but "partitioning" and "extending effective context capacity" overlap with the skill family's adjacent entries (multi-agent-patterns, context-compression, filesystem-context) that the body itself lists. Matches 'mostly distinct; minor overlap risk with closely related skills'. Not 5: those overlap points are real since this collection defines near-neighbor skills.