{"version":"2.1.312","anchor":"mcp-tool-calls-over-http-get-a-mark-in-meta-gated-by-tengu","canonical_anchor":"mcp-tool-calls-over-http-get-a-mark-in-meta-gated-by-tengu","heading":"Tool calls to some HTTP MCP servers now carry an extra mark","tier":"internal","area":"MCP","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.312\/e\/mcp-tool-calls-over-http-get-a-mark-in-meta-gated-by-tengu","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.312","markdown":"### Tool calls to some HTTP MCP servers now carry an extra mark\n\nTool calls to some HTTP MCP servers now include an extra generated mark in their metadata, and one error message is worded differently\n\n**Unclear.** It is not stated what the mark contains or which server addresses get it.\n\n**What**\n\nMCP servers are outside programs that give Claude Code extra tools. When Claude Code calls a tool on an MCP server that it reaches over HTTP (the protocol web pages use), and the server's address passes a check, the call now includes a generated mark in its `_meta` field. That field carries extra details alongside a request. The mark is added only when the call does not already carry an ID linking it to one of Claude Code's tool calls. A tool call is a single request Claude makes to use a tool.\n\nThis sits behind a setting that is on when the server sends nothing for it.\n\nThe same change affects calls that carry no such ID:\n\n- If the server's answer stream ends with no answer, the error now names the MCP server and the tool and says the stream ended with no answer, instead of using the shared wording.\n\n- Claude Code's watchdog, which stops calls that hang, keeps track of these calls separately rather than in the shared list.\n\n**Why**\n\nIf you run an HTTP MCP server, the metadata it receives from Claude Code can now contain this extra mark. The reworded error also tells you which server and which tool stopped answering.\n\n- Flag `tengu_rippling_map`: Not enough to say (read for one account on one subscription tier against v2.1.312; this account: no value returned, anonymous baseline: no value returned, compiled default: on) These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.\n- Area: MCP\n- Tier: Under the hood\n- Useful: 2\/5\n- Signal: 3\/5\n- Scope: individual\n- Heads-up: no"}