Symptom

On the three Show Case cards (writing / document-processing / data-analysis), clicking a card should trigger the bundled skill's Step 1 "Clarify" and invoke AskUserQuestion to gather inputs before acting.

Observed (local dev, bun --cwd packages/desktop-electron dev):

• writing-assistant: asks questions reliably
• document-processing: often skips questions, proceeds with assumed defaults
• data-analysis: often skips questions, proceeds with assumed defaults

Root cause (hypothesis)

Not a code-level bug. Verified in this session that all three skills have structurally identical prompts:

• skills/writing-assistant/SKILL.md
• skills/document-processing/SKILL.md
• skills/data-analysis/SKILL.md

Each has the same <GATE> block, same 3-step workflow, same Step 1 Clarify section phrased as "ask the user ..." in natural language. None names AskUserQuestion by tool name.

The divergence is LLM-level non-determinism: writing tasks are information-sparse (the model has nothing to default to → must ask), while document and analysis cards arrive with strong implicit framing (Excel / CSV / Word file types) that lets the model confidently skip clarification and proceed directly.

Invocation path (for reference)

• Card click → session-new-view.tsx start() calls sdk.client.session.create({ skill: name }) then sdk.client.session.command(buildSkillSessionCommandInput(...)) with command: name
• session.ts routes POST /:sessionID/command to SessionPrompt.command()
• command/index.ts registers skills as commands with the SKILL.md body as the template (no hints, no $ARGUMENTS substitution)

Suggested fixes (ordered by cost)

1. Strengthen Step 1 in document/analysis skills: explicitly name the tool. Change "ask the user ..." to "YOU MUST call the AskUserQuestion tool to ask ... before doing anything else". Do not ship without this line; the tool-name mention materially changes behavior. Cost: edit 2 SKILL.md files.
2. Front-load required-inputs list: add a "Required inputs" bullet list at the top of each skill and make Step 1 say "If any required input is missing, call AskUserQuestion to collect it". This removes the "can infer from file type" shortcut. Cost: edit 2 SKILL.md files.
3. (If 1+2 still flaky) Add an explicit gate/guard rail in command/index.ts that prepends a tool-directive preamble to skill templates so the skill prompt becomes: [preamble: you MUST call AskUserQuestion first unless all X, Y, Z are provided] + <skill body>.

Out of scope

• This is a product/prompt bug, not a regression from PR chore(branding): strip OpenCode residue for Phase 1 #18 (branding cleanup). Pure prompt engineering.
• Writing skill already works; don't touch it.

Acceptance

Clicking document-processing or data-analysis card should reliably (N=5 trials) invoke AskUserQuestion before any tool call against files.