@@ -8,9 +8,14 @@ import type { SerializedBlock } from '@/serializer/types'
 
 /**
  * These assertions are about what the real block registry publishes, so the global stub — which
- * returns one mock block with no outputs — would make every case here pass vacuously.
+ * returns one mock block with no outputs — would make every case here pass vacuously. Only the
+ * generic webhook block is read, so only it is registered.
  */
 vi.unmock('@/blocks/registry')
+vi.mock('@/blocks/registry-maps', async () => {
+  const { partialBlockRegistry } = await import('@sim/testing/mocks/block-registry.mock')
+  return partialBlockRegistry(await import('@/blocks/blocks/generic_webhook'))
+})
 
 function triggerBlock(type: string, params: Record<string, unknown> = {}): SerializedBlock {
   return {
 
@@ -9,11 +9,16 @@ import { beforeEach, describe, expect, it, vi } from 'vitest'
  * off `@/tools/registry`.
  *
  * The sibling suite exercises this tool's gating against a mocked registry; this
- * one runs it against the real block registry and the real generated tool
+ * one runs it against the real Slack block config and the real generated tool
  * metadata, because the thing worth proving is exactly that the metadata
- * artifacts can answer everything the executable registry used to.
+ * artifacts can answer everything the executable registry used to. Only the
+ * Slack block is read, so only it is registered.
  */
 vi.unmock('@/blocks/registry')
+vi.mock('@/blocks/registry-maps', async () => {
+  const { partialBlockRegistry } = await import('@sim/testing/mocks/block-registry.mock')
+  return partialBlockRegistry(await import('@/blocks/blocks/slack'))
+})
 
 const mocks = vi.hoisted(() => ({
   getUserPermissionConfig: vi.fn(),
 
@@ -1,18 +1,21 @@
 /**
  * @vitest-environment node
  */
-import { describe, expect, it, vi } from 'vitest'
+import { describe, expect, it } from 'vitest'
 import {
   getInternalToolOperationHandler,
   getRegisteredInternalToolOperationIds,
   isInternalToolOperationRegistered,
 } from '@/lib/internal/tool-operations/registry.server'
-import { tools } from '@/tools/registry'
 import { getToolIds } from '@/tools/tool-ids'
-import { isInternalToolConfig } from '@/tools/types'
-
-vi.unmock('@/tools/registry')
 
+/**
+ * Registration is checked against the generated tool ids rather than the
+ * executable registry, whose import costs more than every handler load below
+ * combined. The converse — that every operation-backed tool in the registry has
+ * a handler here — is the in-process half of the transport partition sweep in
+ * `tools/request-transport.test.ts`, which already pays for that registry.
+ */
 describe('internal tool operation registry', () => {
   it('registers only canonical internal tool definitions with loadable handlers', async () => {
     const registeredIds = getRegisteredInternalToolOperationIds()
@@ -22,29 +25,15 @@ describe('internal tool operation registry', () => {
 
     for (const toolId of registeredIds) {
       expect(canonicalIds.has(toolId), `Missing canonical tool definition for ${toolId}`).toBe(true)
-      expect(await getInternalToolOperationHandler(toolId)).toBeTypeOf('function')
+    }
+    const handlers = await Promise.all(registeredIds.map(getInternalToolOperationHandler))
+    for (const [index, handler] of handlers.entries()) {
+      expect(handler, `${registeredIds[index]} has no loadable handler`).toBeTypeOf('function')
     }
     // Cost scales with the number of registered internal tools, so this budget has to grow
     // with the registry rather than sit just above the current total.
   }, 90_000)
 
-  it('registers every operation-backed tool and keeps it free of HTTP request metadata', async () => {
-    const operationTools = Object.entries(tools).filter(([, tool]) => isInternalToolConfig(tool))
-
-    expect(operationTools.length).toBeGreaterThan(0)
-    for (const [toolId, tool] of operationTools) {
-      expect(tool.request, `${toolId} must not declare an HTTP request`).toBeUndefined()
-      expect(tool.operation.input, `${toolId} must materialize its operation input`).toBeTypeOf(
-        'function'
-      )
-      if (toolId === 'function_execute' || toolId === 'workflow_executor') continue
-      expect(
-        isInternalToolOperationRegistered(toolId),
-        `${toolId} is missing its in-process operation handler`
-      ).toBe(true)
-    }
-  })
-
   it('loads dynamic MCP operations without an HTTP route', async () => {
     expect(isInternalToolOperationRegistered('mcp-server-id-tool-name')).toBe(true)
     expect(await getInternalToolOperationHandler('mcp-server-id-tool-name')).toBeTypeOf('function')
 
@@ -16,9 +16,14 @@ import { describe, expect, it, vi } from 'vitest'
 
 /**
  * The canonical form reads declared defaults, so the globally-mocked registry
- * (every block reduced to `subBlocks: []`) would make this pass vacuously.
+ * (every block reduced to `subBlocks: []`) would make this pass vacuously. Only
+ * the webhook block is read, so only it is registered.
  */
 vi.unmock('@/blocks/registry')
+vi.mock('@/blocks/registry-maps', async () => {
+  const { partialBlockRegistry } = await import('@sim/testing/mocks/block-registry.mock')
+  return partialBlockRegistry(await import('@/blocks/blocks/generic_webhook'))
+})
 
 import { generateWorkflowDiffSummary } from '@/lib/workflows/comparison/compare'
 import type { WorkflowState } from '@/stores/workflows/workflow/types'
 
@@ -4,7 +4,15 @@
 import { afterAll, describe, expect, it, vi } from 'vitest'
 import type { BlockState } from '@/stores/workflows/workflow/types'
 
+/**
+ * The backfill reads the WhatsApp block's declared sub-blocks, which the global
+ * registry stub empties. Only that block is registered.
+ */
 vi.unmock('@/blocks/registry')
+vi.mock('@/blocks/registry-maps', async () => {
+  const { partialBlockRegistry } = await import('@sim/testing/mocks/block-registry.mock')
+  return partialBlockRegistry(await import('@/blocks/blocks/whatsapp'))
+})
 
 import * as blocksBarrel from '@/blocks'
 import { getBlock as getRealBlock } from '@/blocks/registry'
 
@@ -1,6 +1,18 @@
 import { describe, expect, it, vi } from 'vitest'
 
+/**
+ * Import parsing migrates sub-block ids against each block's declared config,
+ * which the global registry stub empties. Only the blocks the fixtures name are
+ * registered.
+ */
 vi.unmock('@/blocks/registry')
+vi.mock('@/blocks/registry-maps', async () => {
+  const { partialBlockRegistry } = await import('@sim/testing/mocks/block-registry.mock')
+  return partialBlockRegistry(
+    await import('@/blocks/blocks/knowledge'),
+    await import('@/blocks/blocks/start_trigger')
+  )
+})
 
 vi.mock('@/lib/api/client/request', () => ({
   requestJson: vi.fn().mockResolvedValue({}),
 
@@ -3,7 +3,18 @@
  */
 import { describe, expect, it, vi } from 'vitest'
 
+/**
+ * Sanitization reads each block's declared sub-block types, which the global
+ * registry stub empties. Only the blocks the cases below name are registered.
+ */
 vi.unmock('@/blocks/registry')
+vi.mock('@/blocks/registry-maps', async () => {
+  const { partialBlockRegistry } = await import('@sim/testing/mocks/block-registry.mock')
+  return partialBlockRegistry(
+    await import('@/blocks/blocks/condition'),
+    await import('@/blocks/blocks/function')
+  )
+})
 
 import { migrateSubblockIds } from '@/lib/workflows/migrations/subblock-migrations'
 import { sanitizeMalformedSubBlocks } from '@/lib/workflows/sanitization/subblocks'
 
@@ -21,17 +21,6 @@ import { NoteBlock } from '@/blocks/blocks/note'
 vi.unmock('@/tools/metadata')
 vi.unmock('@/tools/metadata-outputs')
 
-/**
- * Uses the real tool registry. Nothing here imports it directly — the dependency
- * is transitive: the search-replace planner resolves tool input params through
- * real subblock configs, so the global `@/tools/registry` mock in
- * vitest.setup.ts empties the data these assertions read.
- *
- * Not a no-op, despite the lack of a direct import. Dropping this opt-out fails
- * 8 tests across this file and its sibling suite.
- */
-vi.unmock('@/tools/registry')
-
 describe('indexWorkflowSearchMatches', () => {
   it('marks generic tool-param fallbacks as non-authoritative', () => {
     expect(
 
@@ -17,17 +17,6 @@ import { WORKFLOW_SEARCH_SUBFLOW_FIELD_IDS } from '@/lib/workflows/search-replac
 vi.unmock('@/tools/metadata')
 vi.unmock('@/tools/metadata-outputs')
 
-/**
- * Uses the real tool registry. Nothing here imports it directly — the dependency
- * is transitive: the search-replace planner resolves tool input params through
- * real subblock configs, so the global `@/tools/registry` mock in
- * vitest.setup.ts empties the data these assertions read.
- *
- * Not a no-op, despite the lack of a direct import. Dropping this opt-out fails
- * 8 tests across this file and its sibling suite.
- */
-vi.unmock('@/tools/registry')
-
 describe('buildWorkflowSearchReplacePlan', () => {
   it('replaces selected text ranges across blocks without touching unselected matches', () => {
     const workflow = createSearchReplaceWorkflowFixture()
 
@@ -5105,6 +5105,10 @@ describe('MCP Tool Execution', () => {
     expect(fetchSpy).not.toHaveBeenCalled()
   })
 
+  /**
+   * `retryDelayMs: 1` rather than `0`: the retry config falls back to the 500 ms
+   * default for a falsy delay, so 1 ms is the smallest delay the tool honors.
+   */
   describe('Tool request retries', () => {
     beforeEach(() => {
       vi.useFakeTimers()
@@ -5118,11 +5122,7 @@ describe('MCP Tool Execution', () => {
       vi.useRealTimers()
     })
 
-    /**
-     * Runs the request with every retry backoff elapsed on the fake clock. A
-     * `retryDelayMs` of 0 falls through to the 500ms default, so the sleeps
-     * between attempts are real unless the clock is faked.
-     */
+    /** Runs the request with every retry backoff elapsed on the fake clock. */
     async function executeWithRetries(params: Record<string, unknown>) {
       const pending = executeTool('http_request', params)
       await vi.runAllTimersAsync()
@@ -5152,7 +5152,7 @@ describe('MCP Tool Execution', () => {
         url: 'https://api.example.com/test',
         method: 'GET',
         retries: 2,
-        retryDelayMs: 0,
+        retryDelayMs: 1,
         retryMaxDelayMs: 0,
       })
 
@@ -5182,7 +5182,7 @@ describe('MCP Tool Execution', () => {
         url: 'https://api.example.com/test',
         method: 'GET',
         retries: 2,
-        retryDelayMs: 0,
+        retryDelayMs: 1,
         retryMaxDelayMs: 0,
       })
 
@@ -5197,7 +5197,7 @@ describe('MCP Tool Execution', () => {
         url: 'https://api.example.com/test',
         method: 'GET',
         retries: 5,
-        retryDelayMs: 0,
+        retryDelayMs: 1,
         retryMaxDelayMs: 0,
       })
 
@@ -5214,7 +5214,7 @@ describe('MCP Tool Execution', () => {
         url: 'https://api.example.com/test',
         method: 'POST',
         retries: 2,
-        retryDelayMs: 0,
+        retryDelayMs: 1,
         retryMaxDelayMs: 0,
       })
 
@@ -5232,7 +5232,7 @@ describe('MCP Tool Execution', () => {
         method: 'POST',
         retries: 1,
         retryNonIdempotent: true,
-        retryDelayMs: 0,
+        retryDelayMs: 1,
         retryMaxDelayMs: 0,
       })
 
@@ -5288,7 +5288,7 @@ describe('MCP Tool Execution', () => {
         url: 'https://api.example.com/test',
         method: 'GET',
         retries: 2,
-        retryDelayMs: 0,
+        retryDelayMs: 1,
         retryMaxDelayMs: 5000,
       })
 
@@ -5308,7 +5308,7 @@ describe('MCP Tool Execution', () => {
         url: 'https://api.example.com/test',
         method: 'GET',
         retries: 1,
-        retryDelayMs: 0,
+        retryDelayMs: 1,
         retryMaxDelayMs: 0,
       })