Names the domain (project plans) and two actions (detects stale plans, suggests session commands), but lacks detail on what 'suggests session commands' means concretely or what specific operations are performed.

Clearly answers both 'what' (detects stale project plans and suggests session commands) and 'when' (explicit 'Triggers on:' clause with multiple trigger phrases), satisfying the requirement for explicit trigger guidance.

Includes a good set of natural trigger terms: 'sync plan', 'update plan', 'check status', 'plan is stale', 'track progress', 'project planning' — these are phrases users would naturally say when needing this skill.

Terms like 'project planning' and 'track progress' are somewhat generic and could overlap with general project management or task tracking skills. However, the specific focus on 'stale plans' and 'session commands' provides some distinctiveness.

Mostly efficient but has some redundancy — the 'Purpose' section restates what the intro already says, and the 'Notes' section repeats the read/write distinction already covered. The 'This skill does NOT manage plans directly' framing is slightly verbose.

Provides concrete command suggestions in a clear table format, but the detection logic sections use pseudocode-like notation rather than executable code or actual implementation. Claude doesn't get instructions on HOW to detect staleness (e.g., actual git commands to check modification dates), just descriptions of what to detect.

The detection scenarios are clearly enumerated and the quick reference table provides a good mapping of situations to actions. However, there's no sequenced workflow for how to actually perform the detection checks, and no validation/feedback loops for confirming whether suggestions were acted upon.

For a skill under 50 lines with a single focused purpose, the content is well-organized with clear sections (Purpose, Detection Logic, Quick Reference, Staleness Heuristics, Notes). No unnecessary external references or deeply nested content.