Plugin MCP tool names can exceed API's 64-character limit

When plugins define MCP servers, Claude Code constructs tool names using the pattern:

mcp__plugin_{plugin_name}_{server_name}__{tool_name}

This can exceed the Anthropic API's 64-character limit for tool names, causing:

API Error: 400 {"type":"error","error":{"type":"invalid_request_error",
"message":"messages.2.content.0.tool_result.content.3.tool_reference.tool_name:
String should have at most 64 characters"}}

Example

The Atlassian plugin (atlassian) with server name atlassian creates prefix mcp__plugin_atlassian_atlassian__ (33 chars). The tool getJiraProjectIssueTypesMetadata (32 chars) results in a 65-character name.

Affected tool:
mcp__plugin_atlassian_atlassian__getJiraProjectIssueTypesMetadata

Suggestions

• Validate tool name length during plugin loading and warn/error
• Use shorter prefixes (e.g., mcp_p_{plugin}_{server}__ or hash-based)
• Document the constraint for plugin authors