diff --git a/package-lock.json b/package-lock.json
index b53a7bf..6fae115 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@linkedapi/mcp",
-  "version": "2.3.18",
+  "version": "2.3.19",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@linkedapi/mcp",
-      "version": "2.3.18",
+      "version": "2.3.19",
       "license": "MIT",
       "dependencies": {
         "@linkedapi/node": "^2.3.19",
diff --git a/package.json b/package.json
index 1a3f313..70540aa 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@linkedapi/mcp",
-  "version": "2.3.18",
+  "version": "2.3.19",
   "description": "MCP server that lets AI assistants control LinkedIn accounts and retrieve real-time data.",
   "main": "dist/index.js",
   "bin": {
diff --git a/src/tools/accept-invitation.ts b/src/tools/accept-invitation.ts
index 20f36bc..a591fb2 100644
--- a/src/tools/accept-invitation.ts
+++ b/src/tools/accept-invitation.ts
@@ -59,32 +59,6 @@ export class AcceptInvitationTool extends OperationTool<TAcceptInvitationParams,
         },
         required: ['invitationType'],
         additionalProperties: false,
-        oneOf: [
-          {
-            properties: {
-              invitationType: { const: 'connect' },
-              personUrl: { type: 'string' },
-            },
-            required: ['invitationType', 'personUrl'],
-            additionalProperties: false,
-          },
-          {
-            properties: {
-              invitationType: { const: 'companyFollow' },
-              companyUrl: { type: 'string' },
-            },
-            required: ['invitationType', 'companyUrl'],
-            additionalProperties: false,
-          },
-          {
-            properties: {
-              invitationType: { const: 'newsletterSubscribe' },
-              newsletterUrl: { type: 'string' },
-            },
-            required: ['invitationType', 'newsletterUrl'],
-            additionalProperties: false,
-          },
-        ],
       } as Tool['inputSchema'],
     };
   }
diff --git a/src/tools/execute-custom-workflow.ts b/src/tools/execute-custom-workflow.ts
index df3d416..c85e0d3 100644
--- a/src/tools/execute-custom-workflow.ts
+++ b/src/tools/execute-custom-workflow.ts
@@ -43,7 +43,7 @@ export class ExecuteCustomWorkflowTool extends OperationTool<
           },
           definition: {
             description: 'A single-action or array workflow definition.',
-            oneOf: [
+            anyOf: [
               {
                 type: 'object',
                 properties: {
@@ -73,7 +73,6 @@ export class ExecuteCustomWorkflowTool extends OperationTool<
             ],
           },
         },
-        anyOf: [{ required: ['actionType'] }, { required: ['definition'] }],
         additionalProperties: true,
       },
     };
diff --git a/src/tools/fetch-post.ts b/src/tools/fetch-post.ts
index 588c44c..a6b1ae9 100644
--- a/src/tools/fetch-post.ts
+++ b/src/tools/fetch-post.ts
@@ -21,7 +21,7 @@ export class FetchPostTool extends OperationTool<TFetchPostParams, unknown> {
       .optional(),
     reactionsRetrievalConfig: z
       .object({
-        limit: z.number().min(1).max(1000).optional(),
+        limit: z.number().min(1).max(500).optional(),
       })
       .optional(),
   });
@@ -84,7 +84,7 @@ export class FetchPostTool extends OperationTool<TFetchPostParams, unknown> {
               limit: {
                 type: 'number',
                 description:
-                  'Optional. Max number of reactions to retrieve. Defaults to 10, with a maximum value of 1000.',
+                  'Optional. Max number of reactions to retrieve. Defaults to 10, with a maximum value of 500.',
               },
             },
           },
diff --git a/src/tools/ignore-invitation.ts b/src/tools/ignore-invitation.ts
index c38a31a..93d7b89 100644
--- a/src/tools/ignore-invitation.ts
+++ b/src/tools/ignore-invitation.ts
@@ -59,32 +59,6 @@ export class IgnoreInvitationTool extends OperationTool<TIgnoreInvitationParams,
         },
         required: ['invitationType'],
         additionalProperties: false,
-        oneOf: [
-          {
-            properties: {
-              invitationType: { const: 'connect' },
-              personUrl: { type: 'string' },
-            },
-            required: ['invitationType', 'personUrl'],
-            additionalProperties: false,
-          },
-          {
-            properties: {
-              invitationType: { const: 'companyFollow' },
-              companyUrl: { type: 'string' },
-            },
-            required: ['invitationType', 'companyUrl'],
-            additionalProperties: false,
-          },
-          {
-            properties: {
-              invitationType: { const: 'newsletterSubscribe' },
-              newsletterUrl: { type: 'string' },
-            },
-            required: ['invitationType', 'newsletterUrl'],
-            additionalProperties: false,
-          },
-        ],
       } as Tool['inputSchema'],
     };
   }
diff --git a/src/tools/search-posts.ts b/src/tools/search-posts.ts
index 2111bc0..45abd7a 100644
--- a/src/tools/search-posts.ts
+++ b/src/tools/search-posts.ts
@@ -25,7 +25,7 @@ const COMPANY_FILTER_ENTRY_SCHEMA = z.union([
 ]);
 
 const PERSON_FILTER_ENTRY_JSON_SCHEMA = {
-  oneOf: [
+  anyOf: [
     {
       type: 'string',
       minLength: 1,
@@ -53,7 +53,7 @@ const PERSON_FILTER_ENTRY_JSON_SCHEMA = {
 };
 
 const COMPANY_FILTER_ENTRY_JSON_SCHEMA = {
-  oneOf: [
+  anyOf: [
     {
       type: 'string',
       minLength: 1,
@@ -202,7 +202,6 @@ export class SearchPostsTool extends OperationTool<TSearchPostsParams, unknown>
               'Optional. URL copied from a LinkedIn content search page after configuring filters. When specified, filter is ignored entirely.',
           },
         },
-        anyOf: [{ required: ['term'] }, { required: ['customSearchUrl'] }],
       } as Tool['inputSchema'],
     };
   }
diff --git a/src/utils/admin-tool.ts b/src/utils/admin-tool.ts
index f3bf34e..711b81d 100644
--- a/src/utils/admin-tool.ts
+++ b/src/utils/admin-tool.ts
@@ -2,6 +2,8 @@ import { LinkedApiAdmin } from '@linkedapi/node';
 import { Tool } from '@modelcontextprotocol/sdk/types.js';
 import z from 'zod';
 
+import { unwrapValueEnvelope } from './unwrap-value-envelope.js';
+
 export abstract class AdminTool<TParams, TResult> {
   public abstract readonly name: string;
   protected abstract readonly schema: z.ZodSchema;
@@ -9,7 +11,7 @@ export abstract class AdminTool<TParams, TResult> {
   public abstract getTool(): Tool;
 
   public validate(args: unknown): TParams {
-    return this.schema.parse(args) as TParams;
+    return this.schema.parse(unwrapValueEnvelope(args, this.getTool().inputSchema)) as TParams;
   }
 
   public abstract execute({
diff --git a/src/utils/linked-api-tool.ts b/src/utils/linked-api-tool.ts
index 5e88297..5b41724 100644
--- a/src/utils/linked-api-tool.ts
+++ b/src/utils/linked-api-tool.ts
@@ -4,6 +4,8 @@ import z from 'zod';
 
 import type { TLinkedApiToolResult, TWorkflowAck } from '../types/linked-api-tool-result.type.js';
 
+import { unwrapValueEnvelope } from './unwrap-value-envelope.js';
+
 interface TLinkedApiToolExecuteOptions<TParams> {
   linkedapi: LinkedApi;
   args: TParams;
@@ -18,7 +20,7 @@ export abstract class LinkedApiTool<TParams, TResult> {
   public abstract getTool(): Tool;
 
   public validate(args: unknown): TParams {
-    return this.schema.parse(args) as TParams;
+    return this.schema.parse(unwrapValueEnvelope(args, this.getTool().inputSchema)) as TParams;
   }
 
   public abstract execute(
diff --git a/src/utils/public-tool.ts b/src/utils/public-tool.ts
index 5075253..43d27ac 100644
--- a/src/utils/public-tool.ts
+++ b/src/utils/public-tool.ts
@@ -1,6 +1,8 @@
 import { Tool } from '@modelcontextprotocol/sdk/types.js';
 import z from 'zod';
 
+import { unwrapValueEnvelope } from './unwrap-value-envelope.js';
+
 // Tools backed by public Linked API endpoints: they get no client and run without any token.
 export abstract class PublicTool<TParams, TResult> {
   public abstract readonly name: string;
@@ -9,7 +11,7 @@ export abstract class PublicTool<TParams, TResult> {
   public abstract getTool(): Tool;
 
   public validate(args: unknown): TParams {
-    return this.schema.parse(args) as TParams;
+    return this.schema.parse(unwrapValueEnvelope(args, this.getTool().inputSchema)) as TParams;
   }
 
   public abstract execute({ args }: { args: TParams }): Promise<TResult>;
diff --git a/src/utils/unwrap-value-envelope.ts b/src/utils/unwrap-value-envelope.ts
new file mode 100644
index 0000000..8257189
--- /dev/null
+++ b/src/utils/unwrap-value-envelope.ts
@@ -0,0 +1,22 @@
+import { Tool } from '@modelcontextprotocol/sdk/types.js';
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === 'object' && value !== null && !Array.isArray(value);
+}
+
+// ChatGPT cannot take a tool whose inputSchema has anyOf/oneOf at its root, and calls such a tool with
+// its arguments wrapped as { value: {...} }. No root combinators are listed any more, but a client
+// can keep calling with a tool list it fetched earlier, so a lone `value` object is still unwrapped
+// for every tool that does not declare a parameter of that name.
+export function unwrapValueEnvelope(args: unknown, inputSchema: Tool['inputSchema']): unknown {
+  if (!isRecord(args) || inputSchema.properties?.['value'] !== undefined) {
+    return args;
+  }
+
+  const { value, ...rest } = args;
+  if (Object.keys(rest).length > 0 || !isRecord(value)) {
+    return args;
+  }
+
+  return value;
+}