memory_* tools: no delete, no append mode, and inconsistent get/save contracts

After several dozen real writes to Project Memory in one project, five gaps stand out. All were hit in practice.

1. There is no memory_delete. Every other group has one (backlog_delete, prompts_delete, teams_delete, triggers_delete) but memory only exposes list / get / save. An agent cannot remove a note it created by mistake — the user must click delete in the app every time. Deleting the mirrored file under .agentsroom/memory/ does nothing: memory_get still returns the note and the file reappears on the next sync. Our workaround is moving notes to a global/recycle_bin/<project> folder via memory_save({folder}), which is a fake trash can — they still appear in memory_list.

2. memory_save can only overwrite the whole note. Adding one paragraph to a 400-line note means pulling the entire note into the agent's context with memory_get, editing, and sending it all back — twice the note's size in tokens to change three lines. A mode: "append", or accepting a content_file path instead of an inline string, would remove that.

3. memory_get returns errors as plain text, not JSON. Normally it returns JSON; when the note does not exist it returns a human sentence. Code that falls back to the raw string when JSON.parse fails treats that sentence as the note body — ours did, and an append against a non-existent note created a new note containing the error message.

4. Parameter names differ between the two tools: memory_get({ note }) vs memory_save({ name }) for the same note.

5. memory_get returns only folderId, never a folder path. Resolving a note's folder requires fetching memory_list and walking folders[].parentId.

AgentsRoom diagnostics

• App version: 1.161.0
• OS: darwin 25.3.0 (arm64)
• Agent CLI: claude
• MCP server: 1.18.0
• App language: en

Problem to solve

Agents cannot delete memory notes at all, and every edit costs a full read plus a full rewrite of the note, so incremental note-keeping is expensive in tokens and takes about 1 second per edit round trip.

Proposed behavior

Add memory_delete (parity with backlog/prompts/teams/triggers). Add mode:"append" or a content_file parameter to memory_save. Return memory_get errors as JSON. Align the note identifier parameter name between memory_get and memory_save. Include the folder path, not just folderId, in memory_get responses.

Who benefits

Any agent maintaining Project Memory across sessions, especially long-running projects where notes grow past a few hundred lines.

Acceptance criteria

An agent can correct its own memory mistakes without asking the user to click delete, and can add a section to a large note without paying to read and rewrite the whole thing.

Latency measured from macOS against agentsroom.dev: ping 23 ms but TTFB 619 ms, so the cost is server-side. memory_get 244-289 ms, memory_save 673-1182 ms, memory_list (17 KB) 587-1516 ms. One note edit is get + save, about 1 s. Fixing the append item would also halve this.