Imported from kok-o/contextos-agents (.agents/core/skills/gemini-precision/SKILL.md). Install upstream with npx skills add kok-o/contextos-agents --skill gemini-precision. Copyright stays with the author.

gemini-precision

Overview

High-precision operational standard designed specifically to harness the high speed and expansive context window of Google Gemini models while eliminating common LLM failure modes: hasty assumptions, partial code placeholders (// ...), unverified assertions, and scope creep.

When to Use

Activate whenever:

• Executing non-trivial code modifications, refactoring, bug fixes, or architecture design.
• The user requires maximum rigor, reliability, and precision from Gemini.
• Handling complex multi-file changes where accidental side-effects must be zero.

Rules & Patterns

1. The Read-Before-Write Invariant (Zero Assumptions)

Never write code based on assumptions about the codebase.

• Before modifying a function or creating an integration, always inspect the actual files using view_file or grep_search.
• Check the exact runtime, framework version, and installed dependencies (e.g. React 19 vs 18, Next.js 15 vs 14, Tailwind v4 vs v3, Zod vs Joi) in package.json or config files before generating code.
• Verify imported symbol names and parameter signatures directly from source files.

2. The Zero-Placeholder Invariant (Complete Code Only)

Never produce lazy, incomplete, or stubbed output.

• ❌ Forbidden:
  • // TODO: implement logic here
  • // ... rest of existing code ...
  • // ... existing imports ...
  • Mock stub returns when real integration is required
• ✅ Mandatory:
  • Provide 100% complete, fully-implemented, compilable, and drop-in ready code.
  • When replacing a block of code, include all necessary imports, type definitions, and edge-case handling.

3. The Proof-of-Work Invariant (Verification Before Completion)

Never claim a task is complete without tool-verified evidence.

• When modifying code or configuration:
  1. Run the project validator or compiler (node .agents/ctx.js validate, tsc --noEmit, etc.).
  2. Run unit and integration tests (npm test, pytest, etc.).
  3. Run linter and formatting checks (npm run lint:md, eslint, etc.).
• If a test or validation fails, do not guess: read the exact error trace, fix the root cause, and re-run until green.

4. Surgical Blast Radius Containment

Modify ONLY what is strictly necessary.

• Keep edits isolated to the exact lines, functions, and files specified in the plan.
• Do not reformat, reorder, or alter indentation of unrelated code blocks.
• Preserve existing comments, docstrings, and project conventions unless explicitly asked to change them.

5. Ponytail Minimalism (YAGNI)

• Prioritize native platform APIs (standard library, browser built-ins) over new npm/pip packages.
• Follow the "Rule of Three": inline on first use, duplicate cleanly on second, abstract only on third.
• Keep solutions obvious to a mid-level developer without requiring multi-layered wrapper classes.

6. Targeted Tool-Specific Modifications

Prevent accidental code loss during file updates.

• For existing files requiring localized updates (< 50% change), always prefer surgical targeted replacement chunks over destructive full-file rewrites.
• Never discard unrelated file sections, existing comments, or helper utilities.

7. Persistent Context & Plan Tracking

Prevent context drift during multi-step tasks.

• When an operation requires more than 3 sequential steps, write and maintain a persistent plan or checklist on disk.
• Never rely exclusively on volatile conversational memory for tracking complex multi-file refactorings.

8. Progressive Step Narration (Transparent Pair Programming)

Eliminate the "black box" by narrating technical decisions.

• Avoid executing long, silent chains of tool calls without user visibility.
• Provide a concise 1–2 sentence transparent status update before key operations:
  • State what was inspected or verified from the code.
  • State the architectural decision made and the immediate next action.
• Keep narration crisp and actionable without excessive verbosity.

Code Examples

Bad (Lazy Model Output) vs Good (Precision Model Output)

❌ Bad (Lazy AI Output):

// user.service.js
export async function updateUser(id, data) {
  // ... existing auth check ...
  // TODO: validate data with zod
  return await db.user.update({ where: { id }, data });
}

✅ Good (Gemini Precision Output):

// user.service.js
import { z } from 'zod';
import { db } from '../lib/db.js';
import { ValidationError, UnauthorizedError } from '../errors/index.js';

const UpdateUserSchema = z.object({
  name: z.string().min(1).max(100).optional(),
  email: z.string().email().optional(),
}).strict();

export async function updateUser(id, data, session) {
  if (!session?.userId || session.userId !== id) {
    throw new UnauthorizedError('Access denied: cannot update another user');
  }

  const parsed = UpdateUserSchema.safeParse(data);
  if (!parsed.success) {
    throw new ValidationError('Invalid update payload', parsed.error.format());
  }

  return await db.user.update({
    where: { id },
    data: parsed.data,
    select: { id: true, name: true, email: true, updatedAt: true }
  });
}

Validation Checklist

• Inspected active codebase files before writing code.
• Delivered 100% complete code with zero // TODO or // ... placeholders.
• Ran automated tests and validation with green status.
• Confined changes to the minimal required blast radius.
• Preserved existing code via targeted edits rather than full-file overwrites.
• Persisted multi-step task state and milestones to disk.
• Narrated progress with concise, transparent step-by-step updates.
• Reported final status with verifiable evidence.

Common Mistakes

• Assuming API contracts: Guessing function parameters without opening the file.
• Premature completion: Declaring "fixed" without running the test suite.
• Uncontrolled refactoring: Rewriting adjacent components while fixing a 1-line bug.

Integration Notes

• Pairs with engineering-workflow to enforce the 6-phase pipeline.
• Enforces the 7-rung ladder of ponytail-mindset.
• Acts as the baseline behavioral guardrail across all Gemini and Antigravity operations.