fix(mcp): answer an unpublishable workflow input on tool updates as validation, and match bare-name alternatives titles (#9367)

* fix(mcp): answer an unpublishable workflow input on tool updates as validation, and match bare-name alternatives titles

Updating a workflow MCP tool's parameter descriptions regenerated its schema without the validation translation the create and add paths use, so a reserved workflow input name returned an internal error instead of a validation failure naming the field. Both paths now share one helper.

The comparison library links scored a title naming a competitor's alternatives only through its mention aliases, which leave out a bare common-word name such as Make. The bare name now counts directly before "Alternatives", so a "Make Alternatives" title ranks first without reading "Make" elsewhere in a title as the competitor.

* test(library): type the comparison fixture's tags so the cast to ContentMeta type-checks

Author: waleedlatif1

apps/sim/app/(landing)/comparisons/library-links.test.ts

@@ -0,0 +1,25 @@
+import { describe, expect, it } from 'vitest'
+import type { ContentMeta } from '@/lib/content/schema'
+import { getComparisonsForPost } from '@/app/(landing)/comparisons/library-links'
+
+function post(title: string, description: string, tags: string[] = []): ContentMeta {
+  return { slug: 'post', title, description, tags } as ContentMeta
+}
+
+describe('getComparisonsForPost', () => {
+  it('ranks a bare common-word competitor first when the title names its alternatives', () => {
+    const [first] = getComparisonsForPost(
+      post('Best Make Alternatives for AI Agents', 'How Zapier and n8n compare for AI agents.'),
+      new Set()
+    )
+    expect(first?.name).toBe('Make')
+  })
+
+  it('does not read the bare common word elsewhere in a title as that competitor', () => {
+    const comparisons = getComparisonsForPost(
+      post('How to Make and Ship AI Agent Alternatives', 'A guide to building AI agents.'),
+      new Set()
+    )
+    expect(comparisons.map(({ name }) => name)).not.toContain('Make')
+  })
+})

apps/sim/app/(landing)/comparisons/library-links.ts

@@ -18,7 +18,10 @@ const LINKS_TO_COMPARISON_SCORE = 2
 const MENTION_SCORE = 1
 
 interface MentionPatterns {
-  /** Matches a title naming the competitor's alternatives ("n8n Alternatives", "LangChain and LangGraph Alternatives"). */
+  /**
+   * Matches a title naming the competitor's alternatives ("n8n Alternatives", "LangChain and LangGraph
+   * Alternatives"). A bare common-word name ("Make") counts only directly before "Alternatives".
+   */
   alternatives: RegExp
   /** Matches Title Case titles and tags, where a bare common-word name ("Make") is ambiguous. */
   subject: RegExp
@@ -38,7 +41,9 @@ function wordPattern(phrases: string[]): RegExp {
 function buildMentionPatterns(competitor: CompetitorProfile): MentionPatterns {
   const aliases = competitor.mentions ?? [competitor.name]
   return {
-    alternatives: new RegExp(`\\b${phraseAlternation(aliases)}(?: and [^,:]+?)? Alternatives\\b`),
+    alternatives: new RegExp(
+      `\\b(?:${phraseAlternation(aliases)}(?: and [^,:]+?)?|${escapeRegExp(competitor.name)}) Alternatives\\b`
+    ),
     subject: wordPattern(aliases),
     mention: wordPattern([competitor.name, ...aliases]),
   }

apps/sim/lib/mcp/orchestration/workflow-mcp-lifecycle.test.ts

@@ -169,6 +169,33 @@ describe('workflow MCP lifecycle orchestration', () => {
     expect(dbChainMockFns.insert).not.toHaveBeenCalled()
   })
 
+  it('answers an unpublishable workflow input on a tool update as a validation failure', async () => {
+    const message = 'Workflow input name "__proto__" is reserved. Rename this input field.'
+    vi.mocked(generateParameterSchemaForWorkflow).mockRejectedValueOnce(
+      new OrchestrationError('validation', message)
+    )
+    dbChainMockFns.limit.mockResolvedValueOnce([{ id: 'server-1' }]).mockResolvedValueOnce([
+      {
+        id: 'tool-1',
+        workflowId: 'wf-1',
+        toolName: 'tool_a',
+        toolDescription: null,
+        parameterSchemaBytes: 10,
+      },
+    ])
+
+    const result = await performUpdateWorkflowMcpTool({
+      workspaceId: 'workspace-1',
+      userId: 'user-1',
+      serverId: 'server-1',
+      toolId: 'tool-1',
+      parameterDescriptionOverrides: { input: 'The request to answer' },
+    })
+
+    expect(result).toEqual({ success: false, error: message, errorCode: 'validation' })
+    expect(dbChainMockFns.update).not.toHaveBeenCalled()
+  })
+
   it('allows updating tool metadata when an unchanged stored schema exceeds the new cap', async () => {
     dbChainMockFns.limit.mockResolvedValueOnce([{ id: 'server-1' }]).mockResolvedValueOnce([
       {

apps/sim/lib/mcp/orchestration/workflow-mcp-lifecycle.ts

@@ -221,6 +221,16 @@ function validateServerToolMetadataBudgetForUpdate(
   return null
 }
 
+/** A workflow's tool input schema, with an input the schema cannot publish answered as a validation failure. */
+async function generateWorkflowMcpBaseSchema(workflowId: string): Promise<Record<string, unknown>> {
+  return generateParameterSchemaForWorkflow(workflowId).catch((error: unknown) => {
+    if (error instanceof OrchestrationError && error.code === 'validation') {
+      throw new WorkflowMcpExpectedError(error.message, 'validation')
+    }
+    throw error
+  })
+}
+
 async function prepareWorkflowMcpTool(params: {
   workflowRecord: WorkflowMcpToolWorkflowRecord
   toolName?: string
@@ -233,14 +243,7 @@ async function prepareWorkflowMcpTool(params: {
   const toolDescription =
     params.toolDescription !== undefined ? params.toolDescription?.trim() || null : null
 
-  const baseSchema = await generateParameterSchemaForWorkflow(workflowRecord.id).catch(
-    (error: unknown) => {
-      if (error instanceof OrchestrationError && error.code === 'validation') {
-        throw new WorkflowMcpExpectedError(error.message, 'validation')
-      }
-      throw error
-    }
-  )
+  const baseSchema = await generateWorkflowMcpBaseSchema(workflowRecord.id)
   const requestedOverrides =
     params.parameterDescriptionOverrides ??
     (params.legacyParameterSchema
@@ -932,7 +935,7 @@ export async function performUpdateWorkflowMcpTool(
         .limit(1)
       if (!toolRow) return { success: false, error: 'Tool not found', errorCode: 'not_found' }
 
-      const baseSchema = await generateParameterSchemaForWorkflow(toolRow.workflowId)
+      const baseSchema = await generateWorkflowMcpBaseSchema(toolRow.workflowId)
       const overrides = pruneOverridesToSchema(
         params.parameterDescriptionOverrides ??
           (params.parameterSchema