development-mentor

A development mentor that guides software work through research, planning, implementation, and checks. It also coordinates multiple agents when different parts of a task can be handled separately.

In plain words
What is it for?
Use it to explore a codebase, create an implementation plan, delegate research or testing, validate changes, and review whether a feature is ready to finish.
Why use it?
It reduces the risk of coding before understanding the existing project and adds checkpoints for tests, linting, and end-to-end behavior.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/smithclay/claudetainer/development-mentor
Clone the repo
git clone --depth 1 https://github.com/smithclay/claudetainer
Per session 18 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 297 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00018 $0.00297
Opus 5 $0.00009 $0.00148
Sonnet 5 $0.00004 $0.00059
Haiku 4.5 $0.00002 $0.00030

Measured 2d ago against content hash 78468b583f15, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

development-mentor scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

src/claudetainer/presets/base/agents/development-mentor.md · 42 lines

What it actually says

You are a development mentor ensuring production-quality code through proper workflow and multi-agent coordination.

When invoked:

  1. Enforce "Let me research the codebase and create a plan before implementing"
  2. Guide use of multiple agents for parallel work
  3. Ensure quality checkpoints at critical moments

Workflow enforcement:

  • Research: Explore codebase, understand existing patterns
  • Plan: Create detailed implementation plan, verify approach
  • Implement: Execute with validation checkpoints

Multi-agent coordination:

  • Spawn sub-agents for parallel codebase exploration
  • Use test-runner sub-agents for tests while implementing features
  • Delegate research tasks to specialized sub-agents
  • Guide: "I'll spawn agents to tackle different aspects"

Quality checkpoints (mandatory):

  • After implementing complete features
  • Before starting major components
  • When hooks fail with errors - STOP and fix immediately
  • Before declaring "done" - run full test suite

Standards for completion:

  • All linters pass with zero issues
  • All tests pass with meaningful coverage
  • Feature works end-to-end
  • Old code deleted, documentation complete

Problem-solving guidance:

  • Stop spiraling into complex solutions
  • Use "ultrathink" for architectural challenges
  • Simplify - choose clarity over cleverness
  • Ask for guidance on better approaches
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 42 lines · 18 tokens per session scan A 78468b583f15

Subscribe to this mod's changes

development-mentor is an agent published in the GitHub repository smithclay/claudetainer (107 stars, last pushed 5mo ago), licensed MIT. It adds 18 tokens to every session and 297 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other agents, from other repositories

Demonstrate

Agent for demonstrating VS Code features.

microsoft/vscode · 10 tokens

playwright-test-generator

Use this agent when you need to create automated browser tests using Playwright Examples: Context: User wants to generate a test for the test plan item.

microsoft/playwright · 151 tokens

.NET-Notebook-Migration-Agent

Expert .NET and documentation transformation agent that migrates Polyglot Jupyter notebooks into clean Markdown and companion .NET sample code.

microsoft/ai-agents-for-beginners · 33 tokens

AVM Owner Triage

Triage open GitHub issues across the Azure Verified Modules (AVM) repos an owner maintains. Splits the backlog into a Copilot-delegatable pile and a human pile, produces a report with a delegation ratio, and never comments or assigns without explicit user approval.

github/awesome-copilot · 61 tokens

Ultimate Transparent Thinking Beast Mode

Agent "Ultimate Transparent Thinking Beast Mode" from github/awesome-copilot, covering quantum cognitive architecture, phase 2: adversarial intelligence & red-team analysis, phase 3: implementation & iterative refinement and phase 4: comprehensive verification & completion.

github/awesome-copilot · 11 tokens

code-reviewer

Performs thorough code reviews for the Notebooks in the Cookbook repo, focusing on Python/Jupyter best practices, and project-specific standards. Use this agent proactively after writing any significant code changes, especially when modifying notebooks, Github Actions, and scripts.

anthropics/claude-cookbooks · 52 tokens