docs: update project descriptions and terminology

- Replace "reasoning-native" and "reasoning-based" with "document
understanding" throughout documentation
- Update README.md to clarify that Vectorless compiles documents
into structured trees and provides reasoning acts, not retrieval
results
- Change "Fusion" to "Synthesis" in architecture diagram
- Update blog post tags from [vectorless, rag, llm, announcement]
to [vectorless, document-understanding, llm, ai, announcement]
- Modify docusaurus config and homepage header/description to
reflect new positioning as "Document Understanding Engine for AI"
- Streamline feature descriptions and remove redundant phrases

Author: zTgx

README.md

@@ -3,7 +3,7 @@
 <img src="https://vectorless.dev/img/with-title.png" alt="Vectorless" width="400">
 
 <h1>Document Understanding Engine for AI</h1>
-<h5>Reason, don't vector · Structure, not chunks · Think, then answer</h5>
+<h3>Reason, don't vector · Structure, not chunks · Think, then answer</h3>
 
 [![PyPI](https://img.shields.io/pypi/v/vectorless.svg)](https://pypi.org/project/vectorless/)
 [![PyPI Downloads](https://static.pepy.tech/badge/vectorless/month)](https://pepy.tech/projects/vectorless)
@@ -14,7 +14,7 @@
 
 </div>
 
-**Vectorless** is a document understanding engine for AI. It reads documents as structured trees of meaning, then dispatches multiple agents to reason through headings, sections, and paragraphs — understanding how each part relates to the whole. The problem it solves is not "where to look", but "what does this mean in context". Every understanding is a **reasoning** act.
+**Vectorless** is a document understanding engine for AI. It compiles documents into structured trees of meaning, then dispatches multiple agents to reason through headings, sections, and paragraphs — evaluating how each part relates to the whole. The problem it solves is not "where to look", but "what does this mean in context". Every answer is a reasoning act, not a retrieval result.
 
 Light up a star and shine with us! ⭐
 
@@ -60,7 +60,7 @@ Engine.query("What drove the revenue decline?")
   │   │
   │   └─ evaluate ── insufficient? → replan → dispatch new paths → loop
   │
-  └─ Fusion ── dedup, LLM-scored relevance, return with source attribution
+  └─ Synthesis ── dedup, evidence scoring, reasoned answer with source chain
 ```
 
 Worker navigation commands:

docs/blog/2026-04-12-welcome/index.mdx

@@ -2,22 +2,22 @@
 slug: welcome
 title: Welcome to Vectorless
 authors: [zTgx]
-tags: [vectorless, rag, llm, announcement]
+tags: [vectorless, document-understanding, llm, ai, announcement]
 ---
 
-Vectorless is a reasoning-native document intelligence engine written in Rust — **no vector database, no embeddings, no similarity search**.
+Vectorless is a document understanding engine for AI. It compiles documents into structured trees of meaning, then dispatches multiple agents to reason through headings, sections, and paragraphs — evaluating how each part relates to the whole. The problem it solves is not "where to look", but "what does this mean in context". Every answer is a reasoning act, not a retrieval result.
 
 {/* truncate */}
 
 ## Why Vectorless?
 
-Traditional RAG systems rely on vector embeddings and similarity search. This approach loses document structure, requires a vector database, and often returns chunks that lack context.
+Understanding a document requires more than finding keywords — it requires navigating structure, cross-referencing sections, and evaluating whether the evidence is sufficient. Vectorless agents do exactly this: they reason through documents the way a human expert would.
 
-Vectorless takes a different path:
+Key capabilities:
 
 - **Hierarchical Semantic Trees** — Documents are parsed into a tree of sections, preserving structure and relationships.
 - **LLM Agent Navigation** — Queries are resolved by agents that navigate the tree using commands (ls, cd, cat, find, grep), making every decision through LLM reasoning.
-- **Zero Infrastructure** — No vector DB, no embedding models, no similarity search. Just an LLM API key.
+- **Zero Infrastructure** — Just an LLM API key, nothing else to deploy.
 
 ## Quick Start
 

docs/docs/intro.mdx

@@ -4,9 +4,7 @@ sidebar_position: 1
 
 # Introduction
 
-**Vectorless** is a reasoning-native document intelligence engine written in Rust — **no vector database, no embeddings, no similarity search**.
-
-It transforms documents into hierarchical semantic trees and uses LLMs to navigate the structure, retrieving the most relevant content through deep contextual understanding instead of vector math.
+**Vectorless** is a document understanding engine for AI. It compiles documents into structured trees of meaning, then dispatches multiple agents to reason through headings, sections, and paragraphs — evaluating how each part relates to the whole. The problem it solves is not "where to look", but "what does this mean in context". Every answer is a reasoning act, not a retrieval result.
 
 ## How It Works
 
@@ -76,12 +74,12 @@ async fn main() -> vectorless::Result<()> {
 ## Features
 
 - **Hierarchical Semantic Trees** — Preserves document structure, not flat chunks
-- **LLM-Powered Agent Navigation** — Worker agents navigate the tree using commands (ls, cd, cat, find, grep), making every retrieval decision through LLM reasoning
+- **LLM-Powered Agent Navigation** — Worker agents navigate the tree using commands (ls, cd, cat, find, grep), making every decision through LLM reasoning
 - **Cross-Reference Resolution** — Automatically resolves "see Section 2.1", "Appendix G" references during indexing
 - **Synonym Expansion** — LLM-generated synonyms for indexed keywords improve recall for differently-worded queries
 - **Orchestrator Supervisor Loop** — Multi-document queries are coordinated by an LLM supervisor that dispatches Workers, evaluates evidence, and replans when needed
 - **Cross-Document Graph** — Automatic relationship discovery between documents via shared keywords
 - **Incremental Indexing** — Content fingerprinting skips unchanged files
 - **DocCard Catalog** — Lightweight document metadata index enables fast multi-document analysis without loading full documents
 - **Multi-Format** — Markdown and PDF support
-- **Zero Infrastructure** — No vector DB, no embedding models, just an LLM API key
+- **Zero Infrastructure** — Just an LLM API key, nothing else to deploy

docs/docusaurus.config.ts

@@ -6,7 +6,7 @@ import type * as Preset from '@docusaurus/preset-classic';
 
 const config: Config = {
   title: 'Vectorless',
-  tagline: 'Reasoning-based Document Engine',
+  tagline: 'Document Understanding Engine for AI',
   favicon: 'img/favicon.ico',
 
   future: {

docs/src/pages/index.tsx

@@ -42,7 +42,7 @@ function HomepageHeader() {
         {/* Left: Brand + Features */}
         <div className={styles.heroContent}>
           <h1 className={styles.mainTitle}>Vectorless</h1>
-          <p className={styles.subTitle}>Reasoning-native Document Engine</p>
+          <p className={styles.subTitle}>Document Understanding Engine for AI</p>
 
           <div className={styles.featureList}>
             <div className={styles.featureItem}>
@@ -119,7 +119,7 @@ export default function Home(): ReactNode {
   return (
     <Layout
       title={`${siteConfig.title}`}
-      description="Reasoning-based document engine. No embeddings, no chunking. Multiple agents navigate your documents to find exactly what's relevant.">
+      description="Document understanding engine for AI. Agents reason through your documents — navigating structure, reading passages, cross-referencing across sections.">
       <HomepageHeader />
       <main />
     </Layout>