Names the domain (marketing tools) and some actions ('plan, evaluate, or build'), but lacks specific concrete actions like 'create calculators, build generators, design interactive widgets' that would make capabilities clearer.

Clearly answers both what ('plan, evaluate, or build a free tool for marketing purposes') and when ('Use when the user mentions...' with explicit trigger list). The 'Also use when' clause provides explicit trigger guidance.

Excellent coverage of natural trigger terms users would say: 'free tool,' 'marketing tool,' 'calculator,' 'generator,' 'interactive tool,' 'lead gen tool,' 'build a tool for leads,' 'free resource,' and 'engineering as marketing.'

Clear niche combining engineering and marketing for lead generation tools. The specific focus on 'engineering as marketing' and 'free tools for leads' creates a distinct category unlikely to conflict with general coding or marketing skills.

Generally efficient but includes some unnecessary framing ('You are an expert...') and explanatory text that could be trimmed. Tables and frameworks are well-structured but some sections like 'Core Principles' state obvious points Claude would infer.

Provides frameworks, checklists, and evaluation criteria but lacks concrete executable examples. No code snippets, specific commands, or copy-paste ready templates. The guidance is structured but remains at the strategic/conceptual level rather than tactical.

Has logical sections and an evaluation scorecard, but lacks explicit step-by-step workflows with validation checkpoints. The 'Initial Assessment' suggests checking context first, but the overall process from ideation to launch isn't sequenced with clear decision points or feedback loops.

Good structure with clear sections, one reference to external file (references/tool-types.md), and related skills listed at the end. Content is appropriately organized with tables for quick scanning and expandable detail where needed.