diff --git a/README.md b/README.md
index 33a4947..cea2bee 100644
--- a/README.md
+++ b/README.md
@@ -258,6 +258,16 @@ Discovers and lists all available namespaces in the configured Pinecone index, i
 }
 ```
 
+### Retrieval tool decision matrix
+
+Use this when choosing among overlapping retrieval tools. **Semantic vs lexical:** use `query` / `query_fast` / `query_detailed` or `query_documents` for meaning-based search; use `keyword_search` for exact or keyword-style matches on the sparse index. **Chunks vs whole documents:** use `query` / `query_fast` / `query_detailed` for ranked chunks; use `query_documents` when you need merged full-document text. **One-shot vs manual flow:** use `guided_query` to run routing, suggestion, and execution in a single call; otherwise call `suggest_query_params` before gated tools.
+
+- **`query` / `query_fast` / `query_detailed`** — Semantic chunk retrieval. Requires `suggest_query_params` to be called first for the target namespace.
+- **`query_documents`** — Semantic search with chunks reassembled into whole documents. Requires `suggest_query_params` to be called first for the target namespace.
+- **`keyword_search`** — Lexical (sparse-only) search. Does not require `suggest_query_params`.
+- **`guided_query`** — Combines namespace routing, suggestion, and query into a single call; no prerequisite tools needed.
+- **`count`** — “How many …?” style counts via semantic search. Requires `suggest_query_params` before use (same gate as `query` / `query_documents`).
+
 ### `suggest_query_params`
 
 Suggests which **fields** to request and which path to use (`count`, or hybrid query presets **fast** / **detailed** / **full** — same vocabulary as the `query` tool `preset` argument), based on the namespace’s schema (from `list_namespaces`) and the user’s natural language query. This is a mandatory flow step before `count` / `query` tools.
diff --git a/src/server/tools/guided-query-tool.ts b/src/server/tools/guided-query-tool.ts
index fa31a3e..241d2df 100644
--- a/src/server/tools/guided-query-tool.ts
+++ b/src/server/tools/guided-query-tool.ts
@@ -25,14 +25,17 @@ function resolveGuidedToolName(
   return 'full';
 }
 
-/** Register the guided_query orchestrator tool on the MCP server. */
+/**
+ * Registers `guided_query` (routing + suggestion + execution in one call).
+ * See "Retrieval tool decision matrix" in README.md for tool-selection guidance.
+ */
 export function registerGuidedQueryTool(server: McpServer): void {
   server.registerTool(
     'guided_query',
     {
       description:
-        'Single orchestrator that runs routing + suggestion + execution in one call. ' +
-        'Flow: optional namespace_router logic -> suggest_query_params logic -> executes count or hybrid query (fast / detailed / full presets). ' +
+        'Combines namespace routing, suggestion, and query into a single call — no prerequisite tools needed. ' +
+        'Single orchestrator: optional namespace_router logic -> executes count or hybrid query (fast / detailed / full presets). ' +
         'Returns decision_trace so behavior stays transparent and debuggable.',
       inputSchema: {
         user_query: z.string().describe('User question or intent.'),
diff --git a/src/server/tools/keyword-search-tool.ts b/src/server/tools/keyword-search-tool.ts
index 88cfc04..45f5066 100644
--- a/src/server/tools/keyword-search-tool.ts
+++ b/src/server/tools/keyword-search-tool.ts
@@ -93,7 +93,10 @@ async function executeKeywordSearch(params: {
   return response;
 }
 
-/** Register the keyword_search tool on the MCP server. */
+/**
+ * Registers `keyword_search` (lexical/sparse-only retrieval).
+ * See "Retrieval tool decision matrix" in README.md for tool-selection guidance.
+ */
 export function registerKeywordSearchTool(server: McpServer): void {
   server.registerTool(
     'keyword_search',
@@ -101,7 +104,7 @@ export function registerKeywordSearchTool(server: McpServer): void {
       description:
         'Keyword (lexical/sparse-only) search over the Pinecone sparse index (default: rag-hybrid-sparse). ' +
         'Use for exact or keyword-style queries. Does not use semantic reranking. ' +
-        'Call list_namespaces first to discover namespaces; suggest_query_params is optional.',
+        'Call list_namespaces first to discover namespaces. Does not require suggest_query_params.',
       inputSchema: {
         query_text: z.string().describe('Search query text (keyword/lexical match).'),
         namespace: z
diff --git a/src/server/tools/query-documents-tool.ts b/src/server/tools/query-documents-tool.ts
index 61abe76..bc9ef7a 100644
--- a/src/server/tools/query-documents-tool.ts
+++ b/src/server/tools/query-documents-tool.ts
@@ -21,7 +21,10 @@ import { jsonErrorResponse, jsonResponse } from '../tool-response.js';
  */
 const CHUNKS_PER_DOCUMENT = 50;
 
-/** Register the query_documents tool (reassemble chunks into full documents) on the MCP server. */
+/**
+ * Registers `query_documents` (reassemble chunks into full documents).
+ * See "Retrieval tool decision matrix" in README.md for tool-selection guidance.
+ */
 export function registerQueryDocumentsTool(server: McpServer): void {
   server.registerTool(
     'query_documents',
@@ -31,7 +34,7 @@ export function registerQueryDocumentsTool(server: McpServer): void {
         'Always uses semantic reranking for document-level relevance (higher latency/cost than chunk-only query). ' +
         'Use for content analysis, summarization, or when you need full-document context. ' +
         'Chunks are grouped by document_number/doc_id/url, ordered by chunk_index when present (e.g. from RecursiveCharacterTextSplitter), and merged into one content per document. ' +
-        'Mandatory flow: call suggest_query_params first. Use list_namespaces to discover namespaces.',
+        'Requires suggest_query_params to be called first for the target namespace. Use list_namespaces to discover namespaces.',
       inputSchema: {
         query_text: z.string().describe('Search query text. Be specific for better results.'),
         namespace: z
diff --git a/src/server/tools/query-tool.ts b/src/server/tools/query-tool.ts
index d83276c..bce6e9d 100644
--- a/src/server/tools/query-tool.ts
+++ b/src/server/tools/query-tool.ts
@@ -108,15 +108,15 @@ const baseSchema = {
 };
 
 /**
- * Single hybrid `query` tool (replaces separate `query_fast` / `query_detailed` MCP tools).
- * Presets mirror the old defaults.
+ * Registers semantic chunk query via one preset-driven `query` tool.
+ * See "Retrieval tool decision matrix" in README.md for tool-selection guidance.
  */
 export function registerQueryTool(server: McpServer): void {
   server.registerTool(
     'query',
     {
       description:
-        'Hybrid semantic search (dense + sparse) with optional reranking. Mandatory flow: call suggest_query_params first. ' +
+        'Hybrid semantic search (dense + sparse) with optional reranking. Requires suggest_query_params to be called first for the target namespace. ' +
         'Use preset=`fast` for low-latency retrieval without reranking and lightweight fields; `detailed` for reranked, content-oriented retrieval; `full` to set use_reranking and fields explicitly.',
       inputSchema: {
         ...baseSchema,