Conciseness

The Steps and how-sure-are-you ladder are tight and every token there earns its place, but the core thesis — 'a convincing-sounding writeup is worthless unless something was run' — is restated three times across 'Mindset' ('A convincing-sounding writeup and a correct one are indistinguishable until something is actually run'), 'Don't trust your own writeup' ('reads as convincing whether or not it's true'), and 'Common Failure Modes to Avoid' ('a blast-radius writeup that sounds right is worthless'). The long porting blockquote and the body intro repeating the description verbatim add further padding. This lands above the 2 anchor (the padding is concentrated in a few sections, not throughout) but below the 4 anchor because the repetition is real and trimmable.

Actionability

For an instruction-only skill the guidance is concrete: named tools ('tokensave_context', 'get_impact_radius_tool'/'get_affected_flows_tool'), a fully specified agent panel ('sonnet/high, opus/xhigh, sonnet/max, fable/high'), and a paste-the-output proof requirement ('Write a script or test that runs the real code, run it, and paste what happened'). It misses the 5 anchor only because there is no example proof script or concrete output artifact shown, leaving the 'common case' unillustrated.

Workflow Clarity

Steps 1-6 are clearly sequenced, the 'Verification' section is an explicit pre-reply checkpoint ('confirm the one safety fact is either proven… or explicitly marked unproven'), and 'Troubleshooting' provides feedback loops for failure recovery (proof script fails, fact unprovable, change too large). This matches the top anchor — explicit validation steps with error-recovery loops — rather than the 4 anchor, which tolerates missing checkpoints.

Progressive Disclosure

The body is a single well-sectioned file with no bundle files (references/, scripts/, assets/ do not exist) and clear, navigable headers matching its structure. It misses the 5 anchor because the skill exceeds 50 lines and carries inline material that arguably belongs in separate files — the multi-paragraph porting/adaptation blockquote and the five 'Common Failure Modes' entries with WHY rationales — leaving minor organization gaps characteristic of the 4 anchor.

Specificity

The description states concrete actions — 'Find what a change could break somewhere else before it ships' and 'prove the one fact it's safe because of by running real code instead of writing it up' — going beyond naming the domain, though coverage is not fully comprehensive. It sits above the 3 anchor ('1-2 concrete actions') because both the discovery and the proof actions are specific, but below 5 because no further actions (e.g., risk reporting, cleared-items summary) are enumerated.

Completeness

Both halves are explicit: what it does ('Find what a change could break… prove the one fact it's safe because of by running real code') and when to use it ('Use for…', an explicit 'Triggers:' list, and a 'DO NOT use for' clause). This matches the anchor requiring concrete trigger phrases for both what and when; the 4 anchor ('when could be more explicit') is clearly surpassed.

Trigger Term Quality

'blast radius of X', 'what could this break', 'is this change safe', 'review this diff', 'what am I missing in this change', and 'reviewing a small diff you don't trust' give comprehensive coverage of natural user phrasing with multiple synonyms. It clearly matches the top anchor and not the 4 anchor, which expects 'a few natural terms missing'.

Distinctiveness Conflict Risk

Distinctive trigger vocabulary ('blast radius', 'what could this break') plus explicit redirects — 'DO NOT use for explaining how existing code works (use how instead) or investigating why it was built that way (use why instead)' — establish a clear niche with minimal conflict risk. The 4 anchor ('minor overlap risk') is surpassed because the disambiguation against the nearest sibling skills is already written into the description.