wa_list_chats

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds a dependency not present in annotations — the call goes 'via Firefox Bridge' — and scopes results to 'visible' chats, warning the agent that results are limited to what is currently rendered rather than the full chat history.

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?

A single front-loaded sentence with the resource, scope qualifier and delivery mechanism, with no filler or repetition of the tool name.

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 no-arg read tool with annotations covering safety and no output schema, the description supplies what is returned (chat names), where it comes from (sidebar) and the transport (Firefox Bridge). It could still state failure conditions, e.g., what happens when Firefox or the sidebar is unavailable, but nothing essential is missing.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; baseline applies. The description does not introduce any spurious arguments.

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?

Names a specific verb and resource ('List visible WhatsApp chat names') plus the exact source ('from the sidebar'), so an agent knows it returns chat labels rather than message bodies. It does not explicitly distinguish itself from wa_read_messages or wa_send_message, though the resource difference is self-evident.

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?

Usage is only implied: the word 'visible' hints that only currently rendered sidebar entries are returned and that the sidebar must be open, which an agent could infer as a prerequisite. There is no explicit when-to-use/when-not statement or named alternative (e.g., use wa_read_messages for content).

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