[BUG] MCP server name containing dot causes API error

Environment

• Platform (select one):
• [ ] Anthropic API
• [X] AWS Bedrock
• [ ] Google Vertex AI
• [ ] Other: <!-- specify -->
• Claude CLI version: 1.0.9
• Operating System: macOS 15.5
• Terminal: iTerm2

Bug Description

A . in the name of an MCP server will cause Claude Code to produce the error API Error: 400 tools.14.custom.name: String should match pattern '^[a-zA-Z0-9_-]{1,64}$' when prompted.

Steps to Reproduce

1. Install an MCP server where the name contains a dot, e.g.: claude mcp add "awslabs.aws-documentation-mcp-server" uvx "awslabs.aws-documentation-mcp-server@latest"
2. Run claude
3. Send a prompt. It will quickly produce the error.

Expected Behavior

There should be no error.

Actual Behavior

The error API Error: 400 tools.14.custom.name: String should match pattern '^[a-zA-Z0-9_-]{1,64}$' is produced.

Additional Context

Seems similar to the bug reported in #467.