# Claude Code v2.1.271: system prompt > 1 of 14 tool descriptions changed. The appended system-reminder blocks moved: 1 line added, 1 line removed. Compared against v2.1.270. Web version: https://changelogs.core-directive.com/prompts/2.1.271?surface=subagent-plan ## What this version holds - model strings captured: 1 - tool descriptions: 14 - compared against: v2.1.270 - system prompt edits: 0 - widest system prompt edit: +0/-0 lines - tool descriptions changed: 1 ## What moved ### Tool: SendMessage (+1/-1 lines) This edit reached all 1 arms. ```diff @@ from line 26 @@ Send the bare name — a name that exactly matches one live agent or session (on this machine, on another machine, or in the cloud) delivers directly. Append the ` [ref]` only when the bare name is not enough — `ListAgents` shows two rows with it, or an error asks you to disambiguate (you typed only a prefix, or a session list could not be checked). A ref you did not just read from a listing or an error will not resolve, and if the same name also names an in-process agent, the bare name always wins — use the in-process one. -A listed peer is alive and will process your message; messages enqueue and drain at the receiver's next tool round (its `ListAgents` row says whether it is busy or idle right now). Your message arrives wrapped as ``. **To reply to an incoming message, copy its `from` attribute as your `to`.** Cross-session messages travel between SESSIONS: if you are a subagent, your send goes out under your parent session's address, and any reply is delivered to the parent session's conversation, not to you. +A listed peer is alive and will receive your message; messages enqueue and drain at the receiver's next tool round (its `ListAgents` row says whether it is busy or idle right now). A successful send means the message reached that session, not that its Claude read it: a session running in a different permission mode than yours holds cross-session messages for its user's approval (and may let them expire), and a session can refuse them outright — for a session on this machine a `[Cross-session delivery notice]` tells you when that happens (the tool result says when this session has no inbox for one to reach); for a Remote Control, cloud or Claude Desktop session nothing reports back, so never treat silence as agreement. Your message arrives wrapped as ``. **To reply to an incoming message, copy its `from` attribute as your `to`.** Cross-session messages travel between SESSIONS: if you are a subagent, your send goes out under your parent session's address, and any reply is delivered to the parent session's conversation, not to you. To hear when a session ON THIS MACHINE finishes what it is doing, pass `notify_when_idle: true` (from the main conversation only) — one-shot and opt-in: exactly one `[Cross-session idle notice]` arrives when it next goes idle (or exits) — shown to you, or only to your user when this session holds peer messages for approval (the tool result says which); if it never signals within the subscription's lifetime (it may still be busy, may refuse inbound requests, or may have ended abruptly) the notice says the subscription expired instead. Omit `message` for a pure subscription that costs that session nothing; include one to deliver it now AND subscribe. Never poll `ListAgents` in a loop or send "are you done?" messages instead. ``` ## Tool descriptions - Bash: https://changelogs.core-directive.com/prompts/2.1.271/tools/Bash.txt?surface=subagent-plan - CronCreate: https://changelogs.core-directive.com/prompts/2.1.271/tools/CronCreate.txt?surface=subagent-plan - CronDelete: https://changelogs.core-directive.com/prompts/2.1.271/tools/CronDelete.txt?surface=subagent-plan - CronList: https://changelogs.core-directive.com/prompts/2.1.271/tools/CronList.txt?surface=subagent-plan - EnterWorktree: https://changelogs.core-directive.com/prompts/2.1.271/tools/EnterWorktree.txt?surface=subagent-plan - ExitWorktree: https://changelogs.core-directive.com/prompts/2.1.271/tools/ExitWorktree.txt?surface=subagent-plan - ListAgents: https://changelogs.core-directive.com/prompts/2.1.271/tools/ListAgents.txt?surface=subagent-plan - Read: https://changelogs.core-directive.com/prompts/2.1.271/tools/Read.txt?surface=subagent-plan - ReportFindings: https://changelogs.core-directive.com/prompts/2.1.271/tools/ReportFindings.txt?surface=subagent-plan - SendMessage (changed in this version): https://changelogs.core-directive.com/prompts/2.1.271/tools/SendMessage.txt?surface=subagent-plan - Skill: https://changelogs.core-directive.com/prompts/2.1.271/tools/Skill.txt?surface=subagent-plan - TaskStop: https://changelogs.core-directive.com/prompts/2.1.271/tools/TaskStop.txt?surface=subagent-plan - WebFetch: https://changelogs.core-directive.com/prompts/2.1.271/tools/WebFetch.txt?surface=subagent-plan - WebSearch: https://changelogs.core-directive.com/prompts/2.1.271/tools/WebSearch.txt?surface=subagent-plan ## Full text - system prompt: https://changelogs.core-directive.com/prompts/2.1.271/system.txt?surface=subagent-plan