diff --git a/packages/tools/registryExecute/README.md b/packages/tools/registryExecute/README.md
index 26dab95..2604bd9 100644
--- a/packages/tools/registryExecute/README.md
+++ b/packages/tools/registryExecute/README.md
@@ -90,10 +90,81 @@ export TPMJS_API_URL=https://registry.mycompany.com
 export TPMJS_EXECUTOR_URL=https://executor.mycompany.com
 ```
 
+## Passing API Keys to Tools
+
+Many tools require API keys to function (e.g., web scraping tools need a Firecrawl key, search tools need an Exa key). The `env` parameter lets you pass these securely.
+
+### How It Works
+
+1. **Search returns required keys**: When you search for a tool, the response includes `requiredEnvVars`:
+   ```json
+   {
+     "toolId": "@firecrawl/ai-sdk::scrapeTool",
+     "requiredEnvVars": ["FIRECRAWL_API_KEY"]
+   }
+   ```
+
+2. **Pass keys when executing**: Include the required keys in the `env` parameter:
+   ```typescript
+   registryExecute({
+     toolId: '@firecrawl/ai-sdk::scrapeTool',
+     params: { url: 'https://example.com' },
+     env: { FIRECRAWL_API_KEY: 'fc-xxx' }
+   })
+   ```
+
+3. **Keys are injected into sandbox**: The executor injects these as environment variables in the isolated Deno runtime where the tool runs.
+
+### Example: Agent with Pre-configured Keys
+
+```typescript
+import { streamText } from 'ai';
+import { anthropic } from '@ai-sdk/anthropic';
+import { registrySearchTool } from '@tpmjs/registry-search';
+import { registryExecuteTool } from '@tpmjs/registry-execute';
+
+// Pre-configure API keys your agent can use
+const API_KEYS = {
+  FIRECRAWL_API_KEY: process.env.FIRECRAWL_API_KEY,
+  EXA_API_KEY: process.env.EXA_API_KEY,
+};
+
+const result = streamText({
+  model: anthropic('claude-sonnet-4-20250514'),
+  tools: {
+    registrySearch: registrySearchTool,
+    registryExecute: registryExecuteTool,
+  },
+  system: `You have access to the TPMJS tool registry.
+When executing tools, use these API keys in the env parameter:
+${JSON.stringify(API_KEYS, null, 2)}
+
+If a tool requires a key you don't have, tell the user.`,
+  prompt: 'Scrape https://example.com and summarize the content',
+});
+```
+
+### Tools Without Required Keys
+
+Some tools don't require any API keys (like `@tpmjs/createblogpost`). For these, you can omit the `env` parameter entirely:
+
+```typescript
+registryExecute({
+  toolId: '@tpmjs/createblogpost::createBlogPostTool',
+  params: {
+    title: 'My Post',
+    author: 'Jane Doe',
+    content: 'Hello world...'
+  }
+  // No env needed
+})
+```
+
 ## Security
 
 - All tools run in a sandboxed Deno environment on Railway
 - API keys are passed per-request, never stored
+- Keys are isolated to the specific tool execution
 - Only registered tools can be executed (no arbitrary code)
 
 ## Related
diff --git a/packages/tools/registryExecute/package.json b/packages/tools/registryExecute/package.json
index 642bb05..8580e67 100644
--- a/packages/tools/registryExecute/package.json
+++ b/packages/tools/registryExecute/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tpmjs/registry-execute",
-  "version": "0.1.1",
+  "version": "0.1.2",
   "description": "Execute tools from the TPMJS registry in any AI SDK agent",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
diff --git a/packages/tools/registrySearch/README.md b/packages/tools/registrySearch/README.md
index 2f15d28..a850e66 100644
--- a/packages/tools/registrySearch/README.md
+++ b/packages/tools/registrySearch/README.md
@@ -82,6 +82,25 @@ Search the TPMJS registry to find AI SDK tools.
 }
 ```
 
+### Understanding `requiredEnvVars`
+
+The `requiredEnvVars` field tells you which API keys a tool needs to function. When executing a tool with `@tpmjs/registry-execute`, pass these keys in the `env` parameter:
+
+```typescript
+// 1. Search finds a tool that needs FIRECRAWL_API_KEY
+const searchResult = await registrySearchTool.execute({ query: 'web scraping' });
+// searchResult.tools[0].requiredEnvVars = ["FIRECRAWL_API_KEY"]
+
+// 2. Execute the tool with the required key
+const result = await registryExecuteTool.execute({
+  toolId: '@firecrawl/ai-sdk::scrapeTool',
+  params: { url: 'https://example.com' },
+  env: { FIRECRAWL_API_KEY: 'fc-xxx' }  // Pass required keys here
+});
+```
+
+Tools with an empty `requiredEnvVars` array don't need any API keys.
+
 ## Environment Variables
 
 | Variable | Default | Description |
diff --git a/packages/tools/registrySearch/package.json b/packages/tools/registrySearch/package.json
index f8aeab0..6c0c7a6 100644
--- a/packages/tools/registrySearch/package.json
+++ b/packages/tools/registrySearch/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tpmjs/registry-search",
-  "version": "0.1.1",
+  "version": "0.1.2",
   "description": "Search the TPMJS tool registry from any AI SDK agent",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",