The body is mostly efficient and well-organized, but the 'Domain Context' paragraph explaining Initial vs Continuous Discovery and the filler 'Think step by step' line could be tightened; not verbose enough for 1, but not fully lean for 3.

Concrete, specific guidance throughout: 'generate 5 specific feature ideas each' with named perspective focus areas, 'Prioritize the top 5 ideas' with explicit weighting criteria, and 'provide reasoning and key assumptions to test'.

A clearly sequenced four-step process (understand -> ideate -> prioritize -> reasoning/assumptions) with no ambiguity; this is an ideation skill so the destructive/batch validation requirement does not apply.

Under 50 lines with no bundle files needed, organized into clear sections (Context, Domain Context, Instructions, Further Reading) and only one-level external links, satisfying the simple-skill allowance for a 3.

Names the domain (product discovery for a new product) and the core action ('Brainstorm feature ideas') plus the three perspectives, but it lists only one action rather than multiple distinct concrete actions, so it falls short of the level-3 anchor.

It explicitly answers both what ('Brainstorm feature ideas... from PM, Designer, and Engineer perspectives') and when ('Use when starting product discovery...'), with an explicit 'Use when' clause, matching the level-3 anchor.

Natural trigger phrases a user would actually say are well covered: 'starting product discovery for a new product', 'exploring features for a startup idea', 'doing initial ideation'.

The niche is clear — 'initial discovery for a new product' — with distinct triggers unlikely to fire for unrelated skills, matching the level-3 anchor; it is well above the generic overlap of level 2.