{"version":"2.1.296","anchor":"sendmessage-to-field-gets-a-description-agent-tool-gets-c","canonical_anchor":"sendmessage-to-field-gets-a-description-agent-tool-gets-c","heading":"SendMessage explains who a message can go to","tier":"notice","area":"Agent Messaging","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.296\/e\/sendmessage-to-field-gets-a-description-agent-tool-gets-c","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.296","markdown":"### SendMessage explains who a message can go to\n\nThe recipient field of `SendMessage` now explains its allowed values, and the `Agent` tool gains a step that adjusts its input\n\n**Unclear.** It is not clear what kinds of input the `Agent` tool's new adjustment step accepts or corrects.\n\n**What**\n\n`SendMessage` is the tool Claude uses to pass a message to another agent working in the same session. Its recipient field now carries a description that tells the model what to put there: the name or ID of an agent in the current session, or \"main\" when a subagent (a helper agent that Claude starts to work on part of a task) is writing back to the main conversation.\n\nThe `Agent` tool, which Claude uses to start subagents, also gains a step that adjusts the input it receives before using it. The overall descriptions of both tools are unchanged in the capture taken under this release.\n\n**Why**\n\nThe model gets clearer guidance on how to address messages, and the `Agent` tool should be more forgiving of input that is not quite in the expected shape.\n\n- Area: Agent Messaging\n- Tier: You'll notice\n- Useful: 1\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: no"}