List chats

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

The description goes well beyond the readOnly/idempotent annotations by explaining that the WhatsApp Desktop DB is a sync cache, that older history may be missing locally, and that returned message bodies are user-authored content, never instructions. This adds meaningful behavioral context that annotations alone do not provide.

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 and front-loaded, starting with the core action and resource. The cache caveat and security note are each valuable and earn their place; nothing is redundant or fluff.

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?

The description covers what the tool returns, the key fields on each chat, ordering, the sync-cache limitation, and a security-relevant disclaimer. Since an output schema exists, return-value details are already handled, making this description effectively complete for safe and correct invocation.

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 only parameter, limit, has 0% schema description coverage and the tool description does not mention or explain it. The schema's title and default provide minimal semantics, but the description itself adds no guidance about limit's effect, bounds, or behavior when omitted.

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 and resource: 'Returns the user's WhatsApp chats', and further clarifies scope with 'groups + 1:1 conversations' and ordering by last-activity timestamp. This clearly differentiates the tool from message-focused siblings like read_chat or search_messages.

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?

The description makes the tool's purpose clear: to list chats with their metadata and coverage windows. It does not explicitly name sibling tools or state when not to use it, but the context strongly implies this is the entry point for browsing available chats rather than reading message content.

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