ToolSearch returns tools with names exceeding 64 character API limit

Bug Description

When using ToolSearch, the API returns a 400 error because some MCP tool names exceed the 64 character limit enforced by the API.

Error Message

API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.46.content.0.tool_result.content.3.tool_reference.tool_name: String should have at most 64 characters"},"request_id":"req_011CXShFugYdu6YzN2HL4YSA"}

Affected Tools

The following tools from claude.ai MCP connectors exceed the 64 character limit:

| Tool Name | Length |
|-----------|--------|
| mcp__claude_ai_Cloudflare_Developer_Platform__search_cloudflare_documentation | 77 |
| mcp__claude_ai_Cloudflare_Developer_Platform__migrate_pages_to_workers_guide | 76 |
| mcp__claude_ai_Zapier__microsoft_outlook_add_attendees_to_calendar_event | 72 |
| mcp__claude_ai_Cloudflare_Developer_Platform__hyperdrive_config_delete | 70 |
| mcp__claude_ai_Cloudflare_Developer_Platform__hyperdrive_configs_list | 69 |
| mcp__claude_ai_Cloudflare_Developer_Platform__hyperdrive_config_edit | 68 |
| mcp__claude_ai_Cloudflare_Developer_Platform__hyperdrive_config_get | 67 |

Root Cause

The naming convention mcp__claude_ai_<Server_Name>__<tool_name> generates names that exceed 64 characters when the server name is long (e.g., "Cloudflare_Developer_Platform").

Suggested Fix

1. Truncate or abbreviate server names in the tool naming convention
2. Or increase the 64 character limit in the API validation
3. Or filter out tools with names > 64 chars from ToolSearch results

Environment

• Claude Code CLI
• Windows 11
• MCP connectors: Cloudflare Developer Platform, Zapier (connected via claude.ai)

Workaround

Disconnect the affected MCP connectors (Cloudflare Developer Platform, Zapier) from claude.ai account settings.