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Sweep 25 Sep 2026 · 19:33Z Build v2.1.283 504 read Stable v2.1.274 Latest v2.1.283 Next v2.1.283 Feeds RSS JSON llms.txt llms-full.txt Unofficial

Claude Code v2.1.280 ·

Tool listing cache key now accounts for a byValueListing flag and PS tool set

The tool-description cache key now also factors in a byValueListing flag and a new tool predicate

Under the hood Internal Changes
JSON All of v2.1.280
Under the hoodTier: how much it should matter to you
1Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
Tool ListingArea: what it touches
Internal ChangesKind: in v2.1.280,
Internal ChangesSection of the release
What

The cache key used for tool descriptions now includes two new components: a PS1:/PS0: marker reflecting a new tool predicate, and a V${byValueListing}: segment added when byValueListing is set. These join the existing withoutToolDescribeHooks component already used in the key.

Why

This ensures the cached tool descriptions are recomputed correctly when these new factors differ, rather than potentially reusing a stale cached entry that doesn't reflect them.

How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtWhat byValueListing and the new tool predicate (PS1/PS0) actually control isn't specified.

See this entry in the whole of v2.1.280 →

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