The description names the domain (PRD-to-SRS translation) and mentions some outputs (constraints, invariants, interfaces, unresolved decisions), but the actions are described at a high level ('translate...into an implementation-ready capability plan') rather than listing multiple concrete discrete actions like 'extract requirements, define interfaces, identify constraints, document open questions.'

The description clearly answers both 'what' (translate PRD intent into implementation-ready capability plans exposing constraints, invariants, interfaces, and unresolved decisions) and 'when' (explicit 'Use when' clause specifying the trigger scenario of needing a PRD-to-SRS lane).

Includes some relevant terms like 'PRD', 'roadmap', 'product discussions', 'SRS', and 'implementation-ready', but uses jargon like 'ECC-native PRD-to-SRS lane' that users are unlikely to naturally say. Missing common variations like 'product requirements', 'spec', 'specification', 'technical design', 'system requirements'.

The skill occupies a clear niche — translating product requirements documents into system requirements specifications with specific outputs (constraints, invariants, interfaces). This is distinct enough from general planning, coding, or documentation skills to avoid conflicts.

The skill is reasonably efficient but includes some unnecessary sections like 'Good Outcomes' (Claude doesn't need motivation) and 'When to Use' is somewhat verbose with overlapping bullet points. The 'Inputs' section explains obvious things like 'read only what is needed.' However, it's not egregiously padded.

The workflow steps are clear conceptually but remain at the level of abstract guidance rather than concrete, executable instructions. There are no real examples of a completed capability plan, no sample input/output pair, and the output format template is a skeleton rather than a filled-in example. The skill describes what to produce but doesn't demonstrate it concretely.

The four-step workflow is clearly sequenced (restate → resolve constraints → define contract → translate to execution), with an explicit decision checkpoint at step 4 (ready / needs review / needs clarification). The handoff step acts as a validation gate, and the output format provides a clear checklist structure including open questions as a blocking mechanism.

The skill references external files like `docs/examples/product-capability-template.md` and other ECC lanes, which is good progressive disclosure. However, the main content itself is somewhat monolithic—the 'When to Use' section, 'Non-Negotiable Rules', 'Inputs', and 'Core Workflow' could benefit from tighter organization. The inline output format template could potentially be a separate reference file given its length.