Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden; it does disclose that this is a PUBLIC WRITE that flushes from local cache to a remote Firestore and that it reports status/synced_count/message. It says nothing about failure modes, idempotency, partial-sync behavior, or permission/auth requirements, which matters for an irreversible remote write.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three compact clauses: a bracketed classification, the core action with source and destination, and the trigger phrases plus return shape. It is front-loaded and every sentence carries information the agent would otherwise lack.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-optional-parameter tool with no output schema and no annotations, the description supplies the write semantics, trigger conditions, and a return shape, which is close to sufficient. Missing error-path and auth details keep it from a 5, but there is no critical gap that would cause a wrong call.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the single `force` parameter is fully documented in the schema, so the baseline of 3 applies. The description's phrase 'flush all unsynced' hints at default behavior but never explains what `force` changes, adding no meaning beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb (flush) and resource (unsynced local-first nodes and commits), plus the exact source (IndexedDB / memory cache) and destination (remote Cloud Firestore). No sibling tool in the list performs cloud sync, so the agent can distinguish it from vault_* or session_* tools without opening a schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives a concrete invocation trigger by listing the user commands that select this tool ("해!", "동기화해", "trigger_cloud_sync"), which is clearer than most usage guidance. It does not state exclusions or when to prefer an alternative (e.g. pi_hydrate or session_handover), so it stops short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.