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Sweep 22 Sep 2026 · 17:19Z Build v2.1.280 501 read Stable v2.1.267 Latest v2.1.280 Next v2.1.280 Feeds RSS JSON llms.txt Unofficial
Claude Code v2.1.268 ·

MCP tool-list telemetry now tracks description length stats

MCP tool-list telemetry now reports total, max, mean, and over-limit counts for tool description lengths

TierUnder the hoodhow much it should matter to you
Useful1my rating, 1 to 5
Signal1worth watching, 1 to 5
AreaMCPwhat it touches
KindInternal Changesin v2.1.268,
Under the hood

MCP tool-list telemetry now reports total, max, mean, and over-limit counts for tool description lengths

What

The tengu_mcp_tools_listed telemetry event, sent when Claude Code lists tools from an MCP server, now includes four new fields about the length of tool descriptions returned by that server: descriptionTotalLength, descriptionMaxLength, descriptionMeanLength, and descriptionOverLimitCount (how many descriptions exceed a configured size limit).

Why

This gives visibility into how verbose an MCP server's tool descriptions are, which can help identify servers whose overly long descriptions might affect performance or context usage.

See this entry in the whole of v2.1.268 →

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