Each tool Claude Code offers the model comes with a description and an input_schema, which is the list of inputs the tool accepts. A new path can send these straight from a recorded prompt snapshot, a saved copy of an earlier prompt, instead of rebuilding the tool. It is used only when all of these hold:
CLAUDE_CODE_REMOTE: this is set- a further internal check passes
- there is no strict schema
- there are no describe hooks, meaning no custom code that rewrites the tool description
tengu_binary_balloon: this gate is on
When the path is used, Claude Code logs prompt_snapshot_tool_build_skip_flag and a batched prompt_snapshot_tool_build_skipped event with counts of skipped tools and skipped MCP tools. The code deciding whether tool inputs stream to the model early was moved into its own helper without changing how it works, still using tengu_fgts and the eagerInputStreaming setting for Vertex and Bedrock. For tengu_binary_balloon, the flag server returned off for this site's account and for an anonymous account.
Skipping the rebuild saves work at the start of a request in remote sessions. It only takes effect where the gate is switched on, so most users will see no difference.
tengu_binary_balloon Off in both readingsThe flag server returned off for the account this site reads and for the anonymous baseline. A reading of off cannot rule out a rollout these two readings sit outside of.
This account: off · anonymous baseline: off · compiled default in v2.1.281: off
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.
tengu_fgts Off by default, switched on for this accountThe shipped code defaults this off, and the flag server returned on for the one account this site reads on this version. That is the reading that makes the entry above worth a second look, and it still says nothing about your account.
This account: on · anonymous baseline: on · compiled default in v2.1.281: off
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.
Read once, for one account on one subscription tier, against v2.1.281. It isn't a statement about your account. What a flag value here can and cannot tell you
The finding does not say what the unnamed internal condition checks.
Improved screen-reader output in /mcp: a disabled server is read as "off" instead of "pending"
New in this build: tengu_binary_balloon