Iterative Retrieval

Iterative Retrieval Pattern

Solves the "context problem" in multi-agent workflows where sub-agents cannot predict what context they need until they start working.

When to Use

• Spawning sub-agents that need codebase context they cannot predict upfront
• Building multi-agent workflows where context is progressively refined
• Encountering "context too large" or "missing context" failures in agent tasks
• Optimizing token usage in agent orchestration

The Problem

Sub-agents are spawned with limited context. They lack knowledge of which files are relevant, what patterns exist, or what terminology the project uses.

Standard approaches fail:

• Send everything: exceeds context limits
• Send nothing: agent lacks critical information
• Guess what's needed: often wrong

The Solution: Iterative Retrieval

A 4-phase loop that progressively refines context (max 3 cycles):

┌───────────────────────────────────────┐
│  DISPATCH → EVALUATE → REFINE → LOOP │
│       ▲                    │          │
│       └────────────────────┘          │
│       Max 3 cycles, then proceed      │
└───────────────────────────────────────┘

Phase 1: DISPATCH

Broad initial query to gather candidate files:

• Start with high-level intent patterns (src/**/*.ts)
• Use domain keywords (authentication, user, session)
• Exclude test files

Phase 2: EVALUATE

Score each retrieved file for relevance (0–1):

• High (0.7–1.0): directly implements target functionality
• Medium (0.5–0.7): contains related patterns or types
• Low (< 0.5): tangentially related or irrelevant
• Identify what context is still missing

Phase 3: REFINE

Update search criteria based on evaluation:

• Add new patterns discovered in high-relevance files
• Add terminology found in the codebase
• Exclude confirmed irrelevant paths
• Target specific gaps

Phase 4: LOOP

Repeat with refined criteria. Stop when:

• 3+ files score ≥ 0.7 with no critical gaps, or
• Max cycles (3) reached

Practical Examples

Bug Fix Context

Task: "Fix the authentication token expiry bug"

Cycle 1:
  DISPATCH: Search for "token", "auth", "expiry" in src/**
  EVALUATE: Found auth.ts (0.9), tokens.ts (0.8), user.ts (0.3)
  REFINE: Add "refresh", "jwt" keywords; exclude user.ts

Cycle 2:
  DISPATCH: Search refined terms
  EVALUATE: Found session-manager.ts (0.95), jwt-utils.ts (0.85)
  → Sufficient context (4 high-relevance files)

Feature Implementation

Task: "Add rate limiting to API endpoints"

Cycle 1:
  DISPATCH: Search "rate", "limit", "api" in routes/**
  EVALUATE: No matches — codebase uses "throttle" terminology
  REFINE: Add "throttle", "middleware" keywords

Cycle 2:
  DISPATCH: Search refined terms
  EVALUATE: Found throttle.ts (0.9), middleware/index.ts (0.7)
  REFINE: Need router patterns

Cycle 3:
  DISPATCH: Search "router", "express" patterns
  EVALUATE: Found router-setup.ts (0.8)
  → Sufficient context

Agent Prompt Template

When retrieving context for this task:
1. Start with broad keyword search
2. Evaluate each file's relevance (0–1 scale)
3. Identify what context is still missing
4. Refine search criteria and repeat (max 3 cycles)
5. Return files with relevance ≥ 0.7

Best Practices

1. Start broad, narrow progressively — initial queries should be exploratory
2. Learn codebase terminology — first cycle often reveals naming conventions
3. Track what's missing — explicit gap identification drives refinement
4. Stop at "good enough" — 3 high-relevance files beat 10 mediocre ones
5. Exclude confidently — low-relevance files rarely become relevant

Related Skills

• continuous-learning — for patterns that improve over time