why
Why
Investigate the motivation and intent behind code. The companion how skill answers what the code does and how it works. why answers what forces led to its shape.
Spawn subagents with the host's subagent tool (the Agent tool in Claude Code) on the parent model. Investigators and the synthesizer need MCP access, so use a subagent type that keeps it (general-purpose in Claude Code). Tell each one not to edit files.
Do not use a read-only subagent type that strips MCP tools. That disables the MCP-backed investigators and the synthesizer's citation spot-checks.
Operating Posture
Operate as a careful, cautious, and precise investigator. Be honest about what you know vs what you're inferring. Read references/epistemics.md for the full confidence framework and phrasing guide. The synthesizer must follow it.
Step 1. Understand the Target and the Question
The target is usually a chunk of code, a pattern, a feature, or a named design decision. The question is usually a design rationale, a tradeoff, a motivating edge case, an external constraint, dead code, or a broad history sweep.
If the target is vague ("why do we do it this way?" with no clear referent), make your best guess from conversation context (open files, the current selection, recent edits, what was just discussed). State your interpretation briefly so the user can redirect if you're off, then proceed.