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

The description adds useful behavioral context beyond the annotations: it states the tool connects live and may take 20–60s, and it discloses the return shape ({ messages_stored }). Annotations already declare readOnlyHint=true and idempotentHint=true, so the bar is lower; the added latency and return info are valuable supplementary details.

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?

The description is information-dense, front-loading the purpose with a clear action and then providing usage guidance, latency, and return value. It is slightly verbose (four sentences) but every sentence conveys essential information, keeping it relatively concise for the amount of context it delivers.

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?

Given the tool's moderate complexity (sync operation, one parameter), the description covers usage timing, latency, and return value. However, it fails to explain the 'account' parameter or mention prerequisites (e.g., authentication via authenticate/connect). This omission reduces completeness, as agents may not know how to supply a valid account.

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?

The single parameter 'account' is completely undocumented—schema description coverage is 0%. The tool description never mentions the parameter, its expected format, or how to obtain valid values (e.g., from whatsapp_list_accounts). This is a significant gap that forces the agent to guess.

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 clearly states the tool refreshes local WhatsApp data (messages, groups, contacts) into the local store. It goes beyond a simple verb+resource statement by specifying the scope (recent messages, groups/contacts lists). It does not explicitly differentiate from the closely related sibling whatsapp_history_backfill, so it loses a point.

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?

Explicitly instructs when to call it: 'BEFORE reading (chats/groups/messages/contacts/search) when results look stale or empty' and provides concrete examples (right after connecting, or an account that hasn't synced recently). It does not mention alternatives or when not to use it, but the context is clear enough for most scenarios.

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