Within-7

agent-builder

Design and build AI agents for any domain. Use when users: (1) ask to "create an agent", "build an assistant", or "design an AI system" (2) want to understand agent architecture, agentic patterns, or autonomous AI (3) need help with capabilities, subagents, planning, or skill mechanisms (4) ask about Claude Code, Cursor, or similar agent internals (5) want to build agents for business, research, creative, or operational tasks Keywords: agent, assistant, autonomous, workflow, tool use, multi-step, orchestration

Within-7 1 Updated 4mo ago

Resources

2
GitHub

Install

npx skillscat add within-7/minto-plugin-tools/agent-builder

Install via the SkillsCat registry.

SKILL.md

Agent Builder

Build AI agents for any domain - customer service, research, operations, creative work, or specialized business processes.

Quick Start

What are you trying to do?

Goal First Step Resources
Understand how agents work Read philosophy references/agent-philosophy.md
Build your first agent Start with 3-5 capabilities references/minimal-agent.py
Fix context pollution Use subagents references/subagent-pattern.py
Generate agent scaffold Run init script scripts/init_agent.py

The Core Philosophy

The model already knows how to be an agent. Your job is to get out of the way.

An agent is not complex engineering. It's a simple loop that invites the model to act:

LOOP:
  Model sees: context + available capabilities
  Model decides: act or respond
  If act: execute capability, add result, continue
  If respond: return to user

That's it. The magic isn't in the code - it's in the model. Your code just provides the opportunity.

The Three Elements

1. Capabilities (What can it DO?)

Atomic actions the agent can perform: search, read, create, send, query, modify.

Design principle: Start with 3-5 capabilities. Add more only when the agent consistently fails because a capability is missing.

2. Knowledge (What does it KNOW?)

Domain expertise injected on-demand: policies, workflows, best practices, schemas.

Design principle: Make knowledge available, not mandatory. Load it when relevant, not upfront.

3. Context (What has happened?)

The conversation history - the thread connecting actions into coherent behavior.

Design principle: Context is precious. Isolate noisy subtasks. Truncate verbose outputs. Protect clarity.

Agent Design Thinking

Before building, understand:

  • Purpose: What should this agent accomplish?
  • Domain: What world does it operate in? (customer service, research, operations, creative...)
  • Capabilities: What 3-5 actions are essential?
  • Knowledge: What expertise does it need access to?
  • Trust: What decisions can you delegate to the model?

CRITICAL: Trust the model. Don't over-engineer. Don't pre-specify workflows. Give it capabilities and let it reason.

Progressive Complexity

Start simple. Add complexity only when real usage reveals the need:

Level What to add When to add it
Basic 3-5 capabilities Always start here
Planning Progress tracking Multi-step tasks lose coherence
Subagents Isolated child agents Exploration pollutes context
Skills On-demand knowledge Domain expertise needed

Most agents never need to go beyond Level 2.

Domain Examples

Business: CRM queries, email, calendar, approvals
Research: Database search, document analysis, citations
Operations: Monitoring, tickets, notifications, escalation
Creative: Asset generation, editing, collaboration, review

The pattern is universal. Only the capabilities change.

Key Principles

  1. The model IS the agent - Code just runs the loop
  2. Capabilities enable - What it CAN do
  3. Knowledge informs - What it KNOWS how to do
  4. Constraints focus - Limits create clarity
  5. Trust liberates - Let the model reason
  6. Iteration reveals - Start minimal, evolve from usage

Anti-Patterns

Pattern Symptoms Why it fails Fix
Over-engineering Complex state machines, workflow engines, planning systems before seeing real usage You're guessing what's needed. The model can reason if you give it capabilities Start with 3-5 capabilities. Add complexity only when real usage reveals the need
Too many capabilities Agent struggles to choose, makes irrelevant calls, gets stuck in loops Decision paralysis. More options = harder to reason about Start with 3-5. Add one at a time when agent consistently fails without it
Rigid workflows Hardcoded step sequences, if-then chains, state machines Can't adapt to edge cases. Model intelligence is wasted Give capabilities, let model decide order. Trust the reasoning
Front-loaded knowledge Massive system prompts, always-load references, verbose policies Context bloat. Expensive tokens, slower responses, degraded performance Load knowledge on-demand. Make it available, not mandatory
Micromanagement Pre-specifying "first do X, then Y", validation rules on every step Undercuts model intelligence. You're doing the thinking Give goal + capabilities. Let model figure out the path
No context isolation Long conversations with multiple subtasks, exploration pollutes main thread Context window fills with irrelevant details. Model loses focus Use subagents for noisy subtasks. Return only summaries

NEVER Do These

  • Don't build a "planning system" before seeing if the model can plan on its own
  • Don't add 10+ capabilities "just in case"
  • Don't hardcode workflows with if-then chains
  • Don't load all knowledge upfront
  • Don't validate every step - let the model reason
  • Don't mix exploration and execution in the same context

Resources

Philosophy & Theory:

  • references/agent-philosophy.md - Deep dive into why agents work

Implementation:

  • references/minimal-agent.py - Complete working agent (~80 lines)
  • references/tool-templates.py - Capability definitions
  • references/subagent-pattern.py - Context isolation

Scaffolding:

  • scripts/init_agent.py - Generate new agent projects

Loading Instructions

MANDATORY - READ ENTIRE FILE: When user asks about agent philosophy, theory, or "why do agents work?", you MUST read `references/agent-philosophy.md` completely. NEVER set range limits when reading this file.

For implementation help:

Task Must Load Do NOT Load
First agent build minimal-agent.py subagent-pattern.py, agent-philosophy.md
Context pollution issues subagent-pattern.py minimal-agent.py
Generate scaffold scripts/init_agent.py Any reference files
Deep theory questions agent-philosophy.md Implementation files

The Agent Mindset

From: "How do I make the system do X?"
To: "How do I enable the model to do X?"

From: "What's the workflow for this task?"
To: "What capabilities would help accomplish this?"

The best agent code is almost boring. Simple loops. Clear capabilities. Clean context. The magic isn't in the code.

Give the model capabilities and knowledge. Trust it to figure out the rest.