Claude Code MCP tool name over 128 characters: does Sume hit it?

No, Sume's hosted MCP tools do not hit Claude Code's 128-character tool-name limit. The longest tool name in the Sume MCP server source on main is avatar-video-previews_generate_video, which is 36 characters. Claude Code's changelog says that a tool name longer than 128 characters used to make every request fail, and that such a tool is now left out with an MCP error that names it.

The Claude Code fix appears in 2.1.292 (October 6, 2026) and again in 2.1.293 (October 7, 2026), according to the Claude Code changelog (read 2026-10-07). The matter is worth a check because a gateway, a wrapper server, or a client that namespaces tools can make a short name long. Sume's own names are short, so the risk sits in what you put in front of the server.

What changed and what the numbers are

The table keeps the vendor line and the Sume numbers apart.

Sume's names

Sume uses underscore names, such as generate_video, jobs_wait, and tools_list. The live ids are whatever tools_list returns for your session, per the MCP overview.

If a tool is missing

If a Sume tool does disappear after you upgrade Claude Code, the name length is not the reason on a direct connection. Look at the layers you added:

• A gateway or proxy that rewrites tool names with a long prefix.
• A wrapper MCP server that re-exports Sume tools under a longer name.
• A scope problem: a session with only mcp:read lists only read-only tools, so paid tools are absent by design.

A two-minute check

Run claude mcp add --transport http sume https://mcp.sume.com/mcp, then ask the agent to call mcp_health and tools_list. Compare the count with what you expect for your credential. The quickstart and OAuth page explain why an OAuth session without write access sees fewer tools than an API-key session.