There is only one tool, so cross-tool misselection is impossible. Within it, the eight modes are described with distinct intents (recall vs context vs orient vs fix), though a few (recall, context, how, orient) overlap enough that an agent may pick the wrong mode on first try.

A single tool named 'deja' has no naming conflicts by definition, and the mode names (recall, blame, fix, how, orient, remember, handoff) are readable lowercase verbs. It deviates from the common verb_noun tool convention by encoding actions as a mode parameter instead of separate named tools, which is a minor structural inconsistency.

One tool multiplexing eight distinct operations is borderline thin for the described scope — the server is effectively an 8-operation session-memory system compressed into a single entry point. It is functional but forces callers through one parameter rather than a clear tool surface.

The modes cover the memory lifecycle well: search past sessions, expand one session, attribute file history, find post-error remedies, discover real command usage, orient in a project, persist a decision, and hand off. Gaps are minor (no explicit list/prune/forget of stored memories), but agents can work around them.